请教几道英语填空题~先谢过~1.I have difficulty ______ him because he misp

请教几道英语填空题~先谢过~
1.I have difficulty ______ him because he mispronounced a lot of words.
答案是understanding,是固定搭配么?为什么不是to do
2.mary’s professor had her ____paper many times before allowing her to present it to the committee
A:rewritten B:to re write C:rewrite D:rewriting
这题我选D,结果答案是C
3.he has no choice but ____ to see him.
go,我选的go,谁告诉我but后到底怎么用do 和to呢?
4.By no means _____our mistakes.
A:we ought ignore B:we ought to ignore c:ought we ignore D:ought we to ignore
我选的C,什么时候加to,什么时候不加?
5.the witness claimed _____a man in the party,but he was not sure whether this was the man.
A:to see B:to have seen C:that he saw D:that has seen
我选的D,这里不是用定从更合适吗
6.The teacher has his students ____a composition every other week.
A:to write B:written C:writing D：write
这题我就彻底迷糊
7.“didn’t the council turn down frank’s proposal?””yes,now he regrets ____it.”
A:to submit B:to have submitted C:having submitted D:submitted
我选的A,
8.John was made ____ day and night.
A:work B:to work C:working D:to be worked
我选C,