3.I don't know what 　　　　　(happen) to him just now.

2.A lot of music and sports magazines 　　　　　　(print) every month.

1.This piece of music 　　　　　(love) by young people.

5.in red, in my books, are marked, the difficult problems.(连词成句)

4.People use computers to search for information.(改为被动句)

　 Computers 　　　　　　　　　　　　to search for information.

3.Did you clean your classroom yesterday?(改为被动句)

　 　　　　　　your classroom 　　　　　　yesterday?

2.People play basketball all over the world.(改为被动句)

　 Basketball 　　　　　　　　　　　　all over the world.

1.Three thieves were caught last night.(对画线部分提问)

　 　　　　　　　　　　　　　　　　　　were caught last night?

15.(　　 )We will go to many places of interest in Beijing, 　　　　to the Great Wall.

　　　　 A.covers　　　　　 B.covering　　　　 C.in cluding　　　 D.in cluded

14.(　　 )Knives 　　　　　cutting things.

　　　　 A.are used　　　　 B.are used to　　 C.used to　　　　 D.are used for