用正确的关系代词(that, who, which)填空。

1．Have you ever seen the boy ________ often talks with you on the net?

2．Who do you think is the most important person ________ has ever lived in the world in China?

3．Is he the man ________ caught a thief yesterday?

4．The books ________ he carried to our classroom are not very new．

5．The suspect and the clues ________ the police are looking for are very important and necessary．

6．Is Jinlin Hotel the tallest building ________ stands in the center of the city?

7．I don't think you are the last person ________ has this kind of problem．

8．Is there anything ________ worries you?

9．He didn't catch the train ________ had been away for half an hour．

10．The shirt ________ he bought from the shop at the corner of the street looks nice on you．

从括号中选择适当的词填空。

He was late for class this morning ________ there was something wrong with his bike．(because, so)