将下列英语句子改为被动语态

题目

将下列英语句子改为被动语态

People use radios to learn English in the past.

 2.Jack will show me the photo. 

3.They have raised much money for the Project Hope. 
4.I often hear Mary sing English songs at home.
5.We mustn’t throw litter about.
7.People can visit planets like Mars. 

答案

Radios are used to learn English by people in the past.

The photo will be shown to me by Jack.

Much money have been raised for the Project Hope by them

Mary is often heard to sing English songs by me at home.

The litter mustn't  be thrown away by us.

Planets like Mars can be visited by people.
以上答案纯属个人见解,