21.—— We have to stop talking here outside. Listen， _______!
—— Hurry up， or we‘ll be late.
A. There goes the bell B. There does the bell go C. There the bell goes D. Goes the bell there
22.The factory _______ we‘ll visit next week is not far from here.
A. where B. to which C. which D. in which
23.—Why didn‘t you buy a new car?
—I would have bought one if I _______ enough money.
A. had B. have had C. would have D. had had
24.There was so much noise that the speaker couldn‘t make himself ________.
A. hear B. heard C. hearing D. to hear
25.This is an important problem _______ too few social scientists have researched.
A. which B. that C. into that D. into which
26.They ________ extensive and possibly dangerous actual flight training.
A. undertake B. undergo C. underplay D. underuse
27.They will get the preparation done early in May.
A. 他们五月初就能让别人准备完工作
B. 他们五月初就能准备好工作
C. 他们早在五月份就能把准备工作做完
D. 他们五月初就能把准备工作做完
28.Weather _______， we‘ll go out for a walk.
A. permitted B. permitting C. permits D. for permitting
29.I don‘t think the charge for overhauling the equipment is excessive in _______ to its size.
A. correspondence B. equation C. proportion D. dimension
30.It is difficult to understand this kind of _______ calculation.
A. intricate B. varied C. indispensable D. equable
