Question

1.It's a very useful book.（用what改为感叹句）

2.This is our teacher's office.(改为一般疑问句）

3.The car hit the tree yesterday.(改为否定句）
4.Mr.Brown said ,"Don't run across the street again,Mary."(改为间接引语）

Answer 1

what a useful book ?
Is this your teacher's office?
The car didn't hit the treeyesterday.
Mr.Brown said to Mary that didn't run across the street again .

Answer 2

1. what a useful book is !

2. Is this our teacher's office?

3. The car didn't hit the tree yesterday.

4. Mr.Brown said (that) not to talk in class.