Passage Three

　　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 puzzled by his decision.

　　D)They were afraid he wasn't fully prepared.

　　18 A)It is more exciting than space travel.

　　B)It is much cheaper than space travel.

　　C)It is much safer than space travel.

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

　　19 A)They both attract scientists' attention

　　B)They can both be quite challenging

　　C)They are both thought-provoking.

　　D)They may both lead to surprising findings.

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

　　B)To provide an excuse for his changeable character.

　　C)To explore the philosophical issues of space travel.

　　D)To explain why he took up underwater exploration.