将下列英语句子改为被动语态

将下列英语句子改为被动语态
1.Chlidren often sing this song.
2.People all over the world know the Great Wall.
3.John answered all the question.
4.Torn broke the window.
5.He told me to wait here for him.
6.Mary is taking care of the children.
7.We built a new bridge over the river last year.
8.People call him little old man.
9.They do not make this kind of watches in Beijing.
10.People speak English in almost all the countries in the world.
11.Tea grows in China.
12.We can finish the work the day after tomorrow.
13.Must I do all the exercises?
14.You must not take the books out of the library.