1. Introduction

Once an English for Specific Purposes (ESP) course has been implemented, it needs to be evaluated to see if it has been accountable enough to help learners achieve the main course objectives (Yang et al., 2023). Evaluation, according to Anthony (2018, p. 122), "… is often the first and the most important concern for many stakeholders." The outcome of this evaluation might necessitate revisions to be made in syllabi, materials, tasks, or methods with the aim of course improvement. The results might also be used by course administrators to make important decisions about teachers. Similarly, at the program level, the outcome of evaluations might be used by senior management to determine how to best use funding and resources for the courses or which courses should be expanded or reduced in size. Despite the significance attributed to it in the literature, very few studies, as Gillet and Wray (2006) argue, have been conducted to gauge the effectiveness of English for Academic Purposes (EAP) courses in practice. Furthermore, they claim that there is little research reporting the success of an EAP course, specifically discussing the extent to which these programs help learners succeed in their discipline. The present research was an attempt to examine the efficiency of the EAP program in an EFL context comparing the students' entry and exit scores.

2. Literature Review

General English Course (GEC) is widely implemented by Iranian universities as a compulsory 3-credit course designed by the Iranian Ministry of Science, Research and Technology. A closer examination of the content of the syllabus indicates that the course is divided into two sections. The first section (12 two-hour sessions) is devoted to reading general English passages whereas for the second section of the syllabus, which forms 18 two-hour sessions, the students are required to practice reading semi-specific texts about their discipline. Considering the ESP taxonomy presented by Hutchinson and Waters (1987), it can safely be claimed that the main objective of the course is teaching/learning EAP and the learners need it for their academic studies rather than for work or training. EAP, on the other hand, according to the same taxonomy, is a subcategory of English for Science and Technology (EST), which in turn is a main division of ESP. In designing and implementing ESP courses some stages and factors are involved (Ajideh, et al., 2018; Anthony, 2018). As Dudley-Evans and St. John (1998) put it “the stages in ESP are needs analysis, course (and syllabus) design, materials selection (and production), teaching and learning, and evaluation” (p. 121).

The present review of the related literature, to make it more relevant, intends to focus on the extreme ends of these stages, namely needs analysis and program evaluation. Other stages are not in the scope of this paper.

In his exquisite short review of the trends in teaching English as a foreign language, Farhady (2006) refers to the modifications which foreign language education has witnessed in the last few decades. These changes have been conducted with the improvement of the outcome of the teaching/learning processes as their main objective in order to help language learners acquire a reasonable competency in English. They were typically materialized in the form of different teaching methods which appeared for rather a short period of time and faded away being replaced by another method simply because of some sort of theoretical as well as practical shortcomings. These failures happened partly because “the field of language teaching was not well equipped enough to accommodate the needs of the learners” (Farhady, 2006, p. 577).

These inadequacies seriously questioned the idea of a one-fits-all-approach to language teaching (Hyland, 2006, cited in Nouri & Mazdayasna, 2014; Long, 2005) and led the scholars to pay special attention to issues such as determining the expected performance of the learners and skill specification. This means that for a language education program to be successful, one minimum requirement is to choose which skill(s) is/are most critical and crucial for the learners (Işık-Taş & Kenny, 2020). In fact, this selectivity is considered as the basis of ESP syllabi. Put another way, the courses are developed with a backdrop of practical constraints which arise with regard to the particular terminal performance expected from a certain group of learners (Hyland & Jiang, 2021a, 2021b).

Needs, according to Brown (2014), can be also specified with regard to a diagnostic view where these needs correspond to linguistic features and skills considered necessary for optimal performance in a target setting. In this view, all the stakeholders can play a role in determining what is necessary with more emphasis assigned to the ideas of stakeholders who have direct knowledge and experience of the target setting. "In the EAP context these can include experienced ESP instructors, course coordinators, head of department and subject specialists as well as future employers and graduate alumni now working in the target field" (Anthony, 2018, p.66). Indeed, investigating needs has been repeatedly reported to be “an accepted principle in language education” (Farhady, 2005, p. 8) and the basis of curriculum/course design and development in different branches of ESP (e.g., Nazari, 2020; Tahririan & Chalak, 2019). Specification of needs, on the other hand, is accomplished through considering a large number of factors with each one assumed to play a role in a particular instructional program. That is why these needs are prepared through multiple sources of information including interviews with the participants or investigating the use situation and examining the specialist discourse (Basturkmen, 2010; Liu & Hu, 2021).

One of the important decisions to be made with regard to the specification of the needs of the learners is skill specification (Farhady, 2006). Put differently, in designing ESP courses, it should be determined in advance which skill(s) is/are most significant for certain groups of learners regarding the future language use context in which they are expected to act.

The ability to comprehend academic texts has been considered by many curriculum developers and course designers as the most important need university students have (Chostelidou, 2010; Dreyer & Nel, 2003; Khany & Tarlani-Aliabadi, 2016; Liu et al., 2011; Nergis, 2013; Smith et al., 2022). Iranmehr et al. (2018, p. 173) state that “the main objective of the EAP programs [in Iran] is claimed to be bridging the gap between the students' General English Proficiency (GEP) and their ability to read authentic discipline-specific texts." These scholars justify their position by claiming that a large amount of scientific and technological information is published in English, so in order to keep up with the latest findings and developments in their fields, students need to have a good command of reading skills. What is more, to obtain a reasonable and acceptable functioning ability in reading, one needs to gain a remarkable amount of L2 vocabulary (Koda, 2007) as well as enough competence in L2 syntax, though the effect of the latter one is still inconclusive (Shiotsu & Weir, 2007).

Nevertheless, the results from some other studies (e.g., Bacha & Bahous, 2008; Evans & Green, 2007; Taillefer, 2007; Zohoorian, 2015) put more emphasis on writing and speaking skills. In another study by Kim (2006), speaking and listening skills were found to be a must for the successful performance of nonnative learners.

Once a course has ended, irrespective of whatever skill has received more attention, or while the course is going on, it is necessary to know how effective the course is and whether it needs revision or not. As Anthony (2018) asserts, "administrators of ESP courses and programs are also concerned with evaluation because it allows them to determine if the learners are making progress and if instructors are facilitating or hindering that progress" (p.122). Despite the significance attributed to this subject in the literature, there is still a paucity of research examining the efficiency and effectiveness of an ESP course (Kaivanpanah et al., 2021).

As a general classification, evaluations are divided into two main categories: formative evaluation or during-the-course evaluation, which, as the name suggests, is conducted while the course is running, and summative or end-of-course evaluation, which is run at the end of the course and “its purpose is to assess impact and to provide information that can be fed into repeat version or related activities” (Dudley-Evans & St. John, 1998, p.128).

It should be noted here that the design pursued in this study was rather exceptional, in that most of the research studies conducted to assess a course have taken data collection procedures such as non-participant observation reports, student and teacher questionnaires, and teachers' self-reports and interviews (e.g., Atai, 2005; Nouri & Mazdayasna, 2014) as well as content analysis of textbooks (e.g., Iranmehr et al., 2018; Vosoughi et al., 2013). The present research employed a pretest-posttest design in order to present a better picture of the overall gain achieved on the part of the EAP learners at the end of a course compared to their entry competence. To that end, the following research question was generated:

Does General English Course lead to higher achievement of language proficiency among EFL students?

3. Method

3.1. Participants

The initial participants of this study were 266 university students (201 boys and 65 girls) majoring in medicine at the Islamic Azad University in Ardabil, Iran. The mother tongues of the students were Azeri-Turkish and Persian. Their age ranged from 19 to 38. These students belonged to all existing intact GEC classes (n=10), which were held during three successive semesters at this university. It is worth mentioning that only 192 students took the pretest and 211 students sat for the posttest. However, the number of participants who were present at both administrations of the test was 137 (94 males and 43 females). Table 1 presents the profile of the participants. Two university professors taught in these classes.

Table 1

Composition of Participants

Note. M = male; F = female; P = present; A = absent; T = total; G = grand.

3.2. Materials

To implement the course objectives elaborated in the course syllabus, two coursebooks were used, each pertaining to one section of the syllabus offered by the Iranian Ministry of Science, Research and Technology for GEC. The first book was Thoughts and Notions by Ackert and Lee (2005) and the second one was English for the Students of Medicine (I) written by Deedari and Ziahosseiny (1989). It is explicitly mentioned in the syllabus that for the second part of the semester a semi-specific (EAP) book published by SAMT (The Organization for Researching and Compiling University Textbooks in Humanities) should be studied.

A valid and reliable test comprising 30 items was also used in this project (See Appendix A). It consisted of 10 vocabulary items and 20 reading comprehension items belonging to four passages (five items each). The passages were related to the materials covered in the two sections of each semester. Two of them were EGP texts and the other two were semi-specific (EAP) ones. Two forms of this test were used following a counterbalanced design. The test validity was confirmed by two ELT experts. Cronbach’s alpha was also used to assess the reliability of the test with a pilot group of 32 learners, which turned out to be 0.78.

3.3. Procedures

At the beginning of each semester, a pretest was administered to gauge the initial proficiency level of the students. The whole semesters were divided into two parts. For the first six weeks of each semester (12 two-hour sessions as a whole), the book Thoughts and Notions was used and for the remaining nine weeks of the semesters (18 two-hour sessions), the book English for the Students of Medicine (I) was utilized. It should be noted that the teachers just taught the course based on the proposed syllabus. This comprised a set of pre-reading, reading, and post-reading tasks as instructed by the books. The same test was administered again at the end of each semester in the form of a posttest. Both teachers followed the same teaching methodology.

3.4. Design and Analyses

This study was a pre-experimental research with a one-group pretest posttest design. Here, the effect of GEC on the achievement of students was studied. So, GEC was the independent variable of the study and students’ English language proficiency was considered as the dependent variable.

Using IBM SPSS software (version 28), the Wilcoxon Signed Rank Test was run to compare the performances of students on the pretest and posttest. The effect size was also calculated to see the strength of the difference.

4. Results

In this section, the results of descriptive and inferential statistical analyses can be seen. The descriptive statistics for the scores of students on the pretest and posttest are presented in Table 2.

Table 2

Descriptive Statistics for Scores on Pretest and Posttest

Table 2 shows that the mean performance of students has improved from pretest to posttest (16.37 ˃ 14.81); however, in order to check the existence of any statistically significant difference between the two performances, the following steps should be taken. First normality checks should be run on the scores in the pretest and posttest. Then based on the results appropriate statistical tests should be applied to seek the difference.

The results of descriptive statistical analysis are followed by the inferential statistical results. Table 3 illustrates the results of the Kolmogorov-Smirnov test to check the normality of the distributions of scores on the pretest and posttest.

Table 3

Kolmogorov-Smirnov Test of Normality

It is evident from Table 3 that the distributions of scores on both tests are not normal (Sig. < .001). This necessitates running a nonparametric test to compare the performances of students on the pretest and posttest. Table 4 depicts the results of the Wilcoxon Signed Rank Test for comparing pretest and posttest scores.

Table 4

Wilcoxon Test on Pretest and Posttest

The result (Sig. < .001) in Table 4 confirms the fact that there is a statistically significant difference between the performances of students in the pretest and posttest. In order to seek the strength of the difference between the pretest and posttest scores of students, the effect size was calculated using Cohen’s d (1988) formula (r = .2). It is almost a small effect, according to Cohen’s guidelines, denoting that although the mean score of participants has increased from 14.81 to 16.37, there seem to be other factors involved, which can be responsible for this small increase.

5. Discussion

This study was conducted with the aim of evaluating GEC (an EAP course) to see if it can lead to betterment of EFL students' English proficiency. Having employed a pretest-posttest design, a very slight improvement in the learners' exit level competence compared to their entry level proficiency was witnessed. This little improvement, despite being statistically significant, was not remarkable with regard to a rather small effect size. A number of factors may warrant consideration regarding this somewhat surprising result.

First and foremost, there is sufficient evidence emanating from the university students’ scores in the entrance examination, which reveals a low proficiency level among the students at the outset (Askari Arani, 2005; Behtary & Davaribina, 2011; Chostelidou, 2010). This problem can have its roots in English instruction in high school. Behtary and Davaribina (2011) also found that the two-credit Prerequisite English Course (PEC), compulsorily taken by weak students in Iranian universities, was not efficient enough to prepare these learners for GEC. In a similar vein, Atai and Tahririan (2004) claim that "the learners’ problems might basically stem from their inadequate GEP [General English Proficiency] level rather than the technicalities of the scientific texts, domain-specific background knowledge, or methodology factor" (p. 272).

A second reason for the lack of expected progress in GEC might be related to the low motivation level of the learners. A number of studies have delved into the relationship between motivation and language learning (Atai, 2005; Dornyei & Ushioda, 2011; Sakai & Kikuchi, 2009). There is no doubt that one way to facilitate the learning process among the students is to specify the demotivating factors and try to take action to remove them.

Last but not least, a mismatch between the latest principles of teaching and assessing reading and the contents and exercises of books introduced for EAP courses is likely to give rise to the current state of affairs. As a case in point, some well-established micro and macro skills of reading (Brown & Lee, 2015) such as skimming, scanning, or semantic mapping are missing in both textbooks covered in GEC. Vosoughi et al. (2013) and Mohammadi and Safayee Moghadam (2015) provided further evidence for this fact. Overall, these findings further support Gillet and Wray (2006), who claimed that very few researchers document EAP programs as successful.

6. Conclusion

This research set out to evaluate the present state of EAP instruction in the Iranian context focusing on GEC. The findings like those of many previous ones were not promising, showing only a minute improvement in the learners' English proficiency. This can be a crucial warning for the educational stakeholders to avoid overestimating the course outcome and to adjust their expectations accordingly. Additionally, it might serve as a reminder to curriculum developers in general and syllabus designers in particular to reconsider the linguistic components to include in the program development process. Based on these findings, educators may also desire to include extralinguistic features such as motivation boosters in their classroom environment to take the most out of the course and act more efficiently.

There were some limitations in this study, making the findings less generalizable. First, with regard to scope, the study was limited to just one university in Iran. Second, the participants were limited to medicine students, a very small proportion of the whole Iranian student population studying in different disciplines. Third, the moderator variable of sex was not controlled because of administrative restrictions.

Other similar research can be conducted with the aim of extending the boundaries of this study and improving its validity. As an example, a study can explore if the proficiency level of learners has the potential to alter the outcomes. Another set of studies can be designed to compensate for the above-mentioned limitations.

Conflict of interest

The author(s) certify/certifies that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in the present research paper.

Appendix

A- Read the following four passages and answer the questions following them. Mark your answers on the answer sheet.

PASSAGE ONE

Thomas Alva Edison lit up the world with his invention of the electric light. Without him, the world might still be a dark place. However, the electric light was not his only invention. He also invented the phonograph, the motion picture camera, and over 1,200 other things. About every two weeks he created something new.

Thomas A. Edison was born in Milan, Ohio, on February 11, 1847. His family moved to Port Huron, Michigan, when he was seven years old. Surprisingly, he attended school for only two months. His mother, a former teacher, taught him a few things, but Thomas was mostly self-educated. His natural curiosity led him to start experimenting at a young age with electrical and mechanical things at home.

When he was 12 years old, he got his first job. He became a newsboy on a train that ran between Port Huron and Detroit. He set up a laboratory in a baggage care of the train so that he could continue his experiments in his spare time. Unfortunately, his first work experience did not end well. Thomas was fired when he accidentally set fire to the floor of the baggage car.

Thomas then worked for five years as a telegraph operator, but he continued to spend much of his time on the job conducting experiments. He got his first patent in 1868 for a vote recorder run by electricity. However, the vote recorder was not a success. In 1870, he sold another invention, a stock-ticker, for $40,000. A stock-ticker is a machine that automatically prints stock prices on a tape. He was then able to build his first shop in Newark, New Jersey.

Thomas Edison was totally deaf in one ear and hard of hearing in the other, but thought of his deafness as a blessing in many ways. It kept conversations short, so that he could have more time for work. He called himself a "two-shift man" because he worked 16 out of every 24 hours. Sometimes he worked so intensely that his wife had to remind him to sleep and eat.

Thomas Edison died at the age of 84 on October 18, 1931, at his estate in West Orange, New Jersey. He left numerous inventions that improved the quality of life all over the world.

1. In his life, Thomas Edison did things in this order:

1. became a telegraph operator, a newsboy, and then got his first patent.
2. became a newsboy, got his first patent, and then became a telegraph operator.
3. got a patent, became a telegraph operator, and then became a newsboy.
4. became a newsboy, a telegraph operator, and then got a patent.

2. In paragraph 3 line 17 the word ‘car’ means …..

1. automobile.
2. coach.
3. machine.
4. vehicle.

3. Edison considered his deafness …..

1. a disadvantage.
2. a blessing.
3. something from a priest.
4. a necessity.

4. Of all the inventions, the ….. was probably the most important for civilization.

1. vote recorder
2. stock ticker
3. light bulb
4. motion picture camera

5. The main idea of this passage is that …..
6. Thomas Edison was always interested in science and inventions, and he invented many important things.

1. Thomas Edison could not keep a job.
2. Thomas Edison worked day and night on his experiments.

1. deaf people make good inventors because they can focus without the distraction of spoken conversation.

PASSAGE TWO

The human skin can suffer from a number of diseases although the face is relatively immune. Constant exposure to air and sun protects the face from a lot of infections that are due to organisms who love dark and damp areas, such as between the toes. But for men, any diseases on the face can affect shaving.

The one face rash which is very common is acne. The complaint is far more common among youths than any other age group, especially young men. Unless a male patient has a desire to grow a beard, I advise him to continue shaving but rather sketchily, skating around the worst spots. He should use a good, unscented soap, or a medicated one.

Eczema of the face is much less common than acne. Again, keep on shaving, but avoid the worst areas as far as possible. Fortunately, eczema rarely lasts for anything like as long as acne.

Impetigo, another skin infection, seems to prefer the face to any other parts of the body surface. Germs affect isolated areas of the face but do not spread outwards from the main areas. Sufferers should seek medical advice since it is very often rapidly cleared up by the appropriate antibiotic drug.

Since the majority of men do not have the time to go to the barber, and therefore do their own shaving, barber’s rash is now a rarity. Even among the few who still attend hairdressing salons, the latter are now almost invariably carefully maintained and have a high standard of hygiene.

Whatever the skin condition from which the face may suffer, the patient must always keep to his own towel. Also, the razor must be thoroughly cleaned after every shave, (though actual scalding is said to blunt the edge). Very occasionally a patient who uses an electric razor gets an allergic rash due to the chrome or nickel in the razor. But it is possible to identify the metal responsible and take precautions.

Finally, use pleasantly warm water for shaving when you have any skin trouble on the face, and don’t follow the shaving by after-shaving lotion until the rash is better. There are plenty of shaving products for men that are available, such as skin soothers or moisturisers, so, if you are not suffering from any infections, there is no reason why you cannot have a close shave and maintain healthy skin.

6. The main idea of the passage is how to …..
7. manage face skin troubles.
8. shave in cases of having skin infections.
9. follow hygienic rules in barber-shops.
10. treat skin problems in the best way.
11. ‘Skating around’ in line 9 means …..
12.  
13.  
14.  
15.  
16. How many different face infections are mentioned in this passage?
17.  
18.  
19. Five
20. Six
21. ‘Keep to’ in line 25 means …..
22.  
23.  
24.  
25.  
26. The writer is probably …..
27. in favor of attending hairdressing salons.
28. not in favor of attending hairdressing salons.
29. in favor of a close shave.
30. not in favor of a close shave.

PASSAGE THREE

At the very top of a rocky, wind-whipped ridge above this sprawling ski resort west of Yellowstone National Park stands a towering grove of ancient whitebark pine trees. They are one of the few living things that thrive in the harshness at such altitudes, and they produce a large nut that is rich in fat and critical to wildlife.

There is mounting concern among biologists and other researchers, however, that global climate change may be creating conditions in and around the park that are inhospitable for the tree. If climate warming is the real, long-term phenomenon that many experts think it is, scientists believe it could set off a series of changes that could kill 90 percent or more of the whitebark pine trees and possibly compromise the future of the threatened grizzly bear.

The whitebark pine produces cones with pea-size nuts that bears eat in the fall. "Of all the vegetable foods in the ecosystem, whitebark pine is probably the most important," said Chuck Schwartz, leader of the Interagency Grizzly Bear Study Team, a federal agency responsible for protection of the bear. "They are critical to the fall fattening process to get the bears through the winter."

10. The word ‘inhospitable’ in line 8 means …..
11. dangerous

1. welcoming
2. far-reaching
3. inviting

11. The main idea of this passage is that .....

1. whitebark pines can live at high altitudes.
2. grizzly bears eat whitebark pine nuts.
3. global warming may be a real problem, but no one knows for sure.
4. global warming is affecting whitebark pines and grizzlies.

12. Grizzly bears need to eat whitebark pine nuts because the nuts …..

1. are the only food available in the park.
2. help the bears fatten up for the winter.
3. contain an important kind of protein.
4. are hard for other animals to open.

13. Chuck Schwartz's job is to ..…

1. manage Yellowstone National Park.
2. protect grizzly bears.
3. protect pine trees.
4. save pine trees from bear damage.

14. Scientists believe that global warming is affecting grizzly bears by ..…

1. making their coats less warm.
2. causing them to have fewer cubs.
3. increasing the number of animals that can kill them.
4. harming the trees that produce their major food.

PASSAGE FOUR

Surgery has always been one of the most effective ways to remove cancers. By the removal of localized growths, the patient may be completely cured. Approaches to treatment may be varied, and may not, in some cases, even include surgery. X-ray or radium treatment is employed successfully in many types of pelvic cancer. Chemical therapy includes hormone treatments of breast and prostate cancer, and also drug management of the leukemias, blood cancers. Often a combination of surgery, X-ray, and drugs is used.

Among the substances being applied in studies of cancer treatment is a product in various forms known as aminopterin and teropterin. A substance called folic acid has the power to stimulate the growth of blood cells. The substance called aminopterin opposes folic acid. Therefore, it has been used in an attempt to control rapid growth of cells, and there seems to be evidence that in some instances it does delay growth because patients may say that they feel better and suffer less pain. In addition, aminopterin has been applied with some success in attacking leukemia.

The use of radioactive isotopes is the most exciting of the recent ap­proaches to the treatment. Since these chemicals are likely to go directly to one tissue of the body, they concentrate in that organ and destroy abnormal tissues there. Cancer of the thyroid has been successfully treated by using radioactive iodine. Iron, sodium, potassium, chlorine, bromine, calcium, strontium, sulphur, carbon, and hydrogen have all been subjected to ex­periments in controlling growths in various parts of the body. Radioactive phosphorus has also been applied externally to warts, moles, and other growths on the surface of the body, and in some instances with apparent success.

The nitrogen mustard chemicals, developed for the use in warfare, have been helpful in destroying cancer cells of the blood. These drugs are used effectively in Hodgkin’s disease, chronic leukemia, and in other forms of blood tumors.

Much remains to be learned about cancer, and much will depend on the cooperation of patients in promptly reporting to their doctor any suspicious signs. Regular yearly checkups aid in early detection of cancers.

15. One of the most effective ways of cancer treatment is …..
16. the removal of localized growth.
17. the exposure to X-ray.
18. chemical therapy.
19. drug management.
20. Aminopterin is one of the substances applied to …..
21. stimulate the growth of blood cells.
22. develop folic acid.
23. control rapid growth of blood cells.
24. develop leukemia.
25. Radioactive isotopes is a recent approach to …..
26. concentrate cancer in one tissue of the body.
27. the treatment of blood cells.
28. control the growth of radioactive iodine.
29. the treatment of the thyroid.
30. The nitrogen mustard chemicals are helpful in …..
31. destroying the affected cells in pelvic cancer.
32. the treatment of growths on the surface of the body.
33. chronic leukemia and other forms of blood tumors.
34. attacking folic acid in the blood.
35. Cancer can be prevented and treated successfully by …..
36. regular yearly checkups.
37. increasing the intake of folic acid.
38. learning more about cancer.
39. consuming mustard.
40. Cancer can be prevented and treated successfully by …..
41. regular yearly checkups.
42. increasing the intake of folic acid.
43. learning more about cancer.
44. consuming mustard.

1. Fill in the blanks with the correct form of the words from the following table to complete the sentences

21. The most modern television cameras are ………………..in that country.
22. A weak body cannot ………………..itself against germs.
23. The nurse is ………………..pencil line into the patient.
24. One ………………..against germs is to keep things clean.
25. This medicine should be ………………..into the muscle.
26. Vaccination is an effective ………………..against some diseases.
27. The human body can ………………..itself against many diseases.
28. If we ………………..this material to the sunlight, it will lose its color.
29. How did the baby ………………..to penicillin? He showed a strong ………………..to the vaccination after two days. He had a high fever.
30. As his body was ………………..to sunlight, he got sun-burnt.