题目内容：

改写被动语态
被动语态
1 He often helps Tom when Tom is in trouple.
2 People speak English in many countries.
3 We saw a bus running towords us at that time.
4 We heard her sing at the party last Sunday.
5 You must take good care of the children.
6 He was writing a book on his computer when his mother came back.
7 We will plant millions of trees this year.
8 She has already told me the news.
9 They are preparing for the exam.
10 Grandma often tells me stories.