第一节：单项填空（共20小题；每小题1分，满分20分）
从每题所给的A、B、C、D四个选项中，选出可以填入空白处的最佳选项。
21. I hope, first of all, that we shall never lose _____ heart in face of _____ failure.
A. the; a B. the; the C. 不填; 不填 D. a; 不填
22. Our English teacher _____ London in a few days. I wonder when earliest plane _____ on Saturday.
A. leaves; takes off B. is leaving; takes off
C. is leaving; is taking of D. will leave; is taking off
23. Now scientists have _____ a new theory for why women live, on average, longer than men.
A. made up for B. come up with C. given out D. put up
24. Hearing the sound, the animal disappeared into the bushes, ____ Mrs. Stone picked up her basket and ran all
