Directions: In this section, you will hear 2
passages. At the end of each passage, you will hear some questions. After you
hear a question, you must choose the best answer from the four choices marked A,
B, C and D. Then mark the corresponding letter on the Answer Sheet with a single
line through the centre. Passage A
Questions 21 to 25 are based on
the passage you have just heard.
A．The lack of air pressure. B．The extremely hot or cold temperatures. C．Exposure to radiation. D．An inadequately ventilated space suit.