第二部分 英语知识运用(共两节，满分35分)
第一节 单项填空(共15小题；每小题1分，满分15分)
请认真阅读下面各题，从题中所给的A、B、C、D四个选项中，选出最佳选项，并在答题卡上将该页涂黑。
21. The police are looking into the cause which ________ the sinking of the ship with about 200 passengers aboard.
A. was resulted in B. resulted from C. resulted in D. was resulted from
22. I won’t tell the student the answer to the math problem until he ________ on it for more than an hour.
A. has been working B. will have worked C. will have been working D. had worked
