20.　　 _________ is often the case, we have worked out the production plan.

19.　　 The novel ________ you’re interested was written by Mark Twain.

18.　　 Some of the roads were flooded, ________ made our journey more difficult.

17.　　 He talked about the teachers and schools ________ he had visited.

16.　　 Do you know the place __________ he borrowed the book?

15. 只有用这种方法你才能提高你的英语水平. (倒装语序)

14. 我真的不想去,但他硬要我去. (insist)

13. 他不可能把他的书带回家了,因为他所有的书都放在桌上. (情态动词+have done)

12. 我拿不准这礼物是谁的? (belong to)

11. 她给了我们食物和衣服,没要求任何回报. (in return)