Questions 17 to 20 are based on the passage you have just heard.

17 A)They wanted to follow his example.

B)They fully supported his undertaking.

C)They were afraid he wasn’t fully prepared.

D)They were puzzled by his decision.

18 A)It is more exciting than space travel.

B)It is much safer than space travel.

C)It is much cheaper than space travel.

D)It is less time-consuming than space travel.

19 A)They both attract scientists’ attention

B)They are both thought-provoking.

C)They can both be quite challenging

D)They may both lead to surprising findings.

20 A)To explore the philosophical issues of space travel.

B)To show how simple the mechanical aids for diving can be.

C)To explain why he took up underwater exploration.

D)To provide an excuse for his changeable character.