题目内容：

 

1.We use knives to cut things. (改为被动语态)

Knives ___________________________cut things by us.

2.Mike returned the storybooks to the library on time. (改为被动语态)

The storybooks ____________________________ to the library on time __________ Mike.

3.Many people write business letters in English. (改为被动语态)

Business letters ___________________ in English__________  many people.

4.The singer was known in China in the 20th century. (对画线部分提问)

_______________________ the singer__________in China?

5.It is designed by Mike. (对画线部分提问)

__________is it ___________________________ ?

6.This book is not useful for today's students.

This book is ______ for today's students.

7.Mary has been in Hong Kong for a month.

Mary ______ Hong Kong a month ago.

8.In the past people thought the earth was flat.

People ______ to think the earth was flat.

9.The family didn't have enough money to send her abroad.

The family couldn't ______ to send her abroad.

10.There were about fifteen people in the room, and most of them were women.

There were about fifteen people in the room, ______ women.