请将下列各句改写成被动语态.
问题描述：
请将下列各句改写成被动语态.
1.People recognize Zheng Wenguang as the father of chinese science fiction.
2.We asked the teacher to explain the sentence again.
3.They are building a new house behind ourschool.
4.They were holding a meeting last night to discuss the problem.
5.The farmer has cut down the tall tree in his garden.
6.They had completed all the work when I arrived.
7.you can divide the books into three griups.
答
1. Zheng Wenguang is recognized by the people as the father of chinese science fiction.2. The teacher was asked by us to explain the sentence again.3. A new house is being built behind our school.4. A...