16. A) Refrain from showing his feelings. C) Argue fiercely.

　　B) Express his opinion frankly. D) Yell loudly.

　　17. A) Getting rich quickly. C) Respecting individual rights.

　　B) Distinguishing oneself. D) Doing credit to one's community.

　　Passage Three

　　Questions 18 to 20 are based on the passage you have just heard.

　　18. A) If they don't involve any risks.

　　B) If they produce predictable side effects.

　　C) When the urgent need for them arises.

　　D) When tests show that they are relatively safe.

　　19. A) Because they are not accustomed to it.

　　B) Because they are not psychologically prepared for it.

　　C) Because their genes differ from those who have been tested for it.

　　D) Because they are less sensitive to it than those who have been tested for it.

　　20. A) They will have to take ever larger doses.

　　B) They will become physically impaired.

　　C) They will suffer from minor discomfort.

　　D) They will experience a very painful process.