21. Animals that live onTibetan plain have to survive inhard climate.
A. the; a B. a; the C. the; the D. a; a
22. People in the west make _______ a rule to buy Christmas presents for their relatives and friends.
A. it B. that C. this D. as
23. The girl’s face looked pale, so our classroom teacher requested that she ________to hospital immediately.
A. send B. be sent C. sending D. should send
24. There was so much noise in the room that the speaker couldn’t make himself ________.
A. being heard B. hearing C. heard D. hear