请帮我做些英语题目吧?谢谢Directions: For each of the following sentences

请帮我做些英语题目吧?谢谢
Directions: For each of the following sentences, there are four choices marked A, B, C and D. Choose the one answer that best completes the sentence.
21. __ ______, he would be able to feed himself and help his family.
A. Without steady wages B. Haven’t steady wages C. With steady wages D. Have steady wages,

22. You buy some reference books when you go to college.
A. could B. will have to
C. must to D. might

23. He didn't pass the final examination. He it.
A. must have prepared for
B. ought to prepare for
C. ought to have prepared for
D. must to prepare for

24. John's father mathematics in this school ever since he graduated from Harvard University.
A. taught B. teaches C. has taught D. is teaching

25. _ ____ is necessary to get up early to catch the train at 7 a.m. tomorrow..
A. That B. It C. What D. This

26. Neither the teacher nor the students __ _____ in the experiment.
A.has succeeded B. have succeeded C. has achieved D. have achieved

27.A young women was coming toward me, ____ _____________.
A. had long and slim figure B. her figure is long and slim
C. her figure was long and slim D. her figure long and slim

28. Silver is the best conductor of electricity, copper it closely.
A. followed B. to follow C. following D. being following

29. I will let Mr Black tell you ___ ________.
A. what has happened to him
B. what had happened to him
C. that has happened to him
D. that had happened to him

30. He looked for the girl whose heart he knew, but ___ _____ face he didn’t.
A. her B.the C.whose D. his