20.
(A) which
(B) where
(C) for which
(D) to which

16. (A) irritations(B) hassles(C) difficulties(D) worries

17. (A) of(B) by(C) with(D) in

18. (A) in search of(B) In presence of(C) in place of(D) in addition to

19. (A) likewise(B) just as(C) similarly(D) by contrast

1. Choose one correct sentence.(A) You have not spoken to me one month ago. Is everything ok?(B) I had gone to Japan for three times. I had a great time there.(C) She has lived in Toronto since last summer. I miss her a lot.(D) We had married in 2015. We love each other so much.

2. Choose one correct sentence.(A) Either John or my brothers are going to go to the concert.(B) Each of the department is responsible for collecting data.(C) Neither my colleague nor my classmate are going to USA.(D) More than one student has reported the project to the teacher.

3. Choose one correct sentence.(A) A backpack stuffed with bread and two piles of files on the desk.(B) The manager, who has no patience waiting for late people, is angry.(C) Because hungry boys open their mouths and grab the food eagerly.(D) Having a piece of pie and some chilled lemonade on a hot sunny Saturday.

4. Choose one correct sentence.(A) She would travel around the world if she could retire next year.(B) If I win the lottery, I would have become a billionaire.(C) John would get married with Kate if they had not broken up.(D) If May had been careful, she would not have that accident.

5. Choose one correct sentence.(A) This is Paul, who I believe you've already met at the conference.(B) Eva's teacher whose she can rely on will retire next year.(C) I need to know whom cleaned the room and mopped the floor.(D) The computer engineer whom I asked for assistance was smart.

6. The following sentences are in the same paragraph. Which if the following is the best topic sentence?(A) America is a country worth visiting for people with different interests and ages.(B) When you're traveling to America, you can visit different cities like Chicago or Atlanta.(C) Cities in the west part of America are usually very modern and prosperous.(D) In fact, America receives millions of visitor per year, which outnumbers some European countries.