1. Knowing English is very useful 

It..........................

2. It started to snow at 5 o'clock

It.........................

3. Nam is taller than Hung 

Hung...............

4. When did you go to bed last night?

What............................

5. What time does Nam have to leave

Do you know.........................

1. He/ wil/ good/ dancing

=>

2. She/ not be/ interested in/ watch/ foodball match

=> 

3. Why/ not/ we/ plant trees/ around our houses/ get shade/ fresh air?

=> 

4. We/ put/ garbage bins/ the schoolyard/ prevent/ lazy student/ throw trash

=>  

3. '' What are you doing ? ''. She asked

-> She asked me.............. doing

4. I don't have a camera, so I can't take photo

-> I wish.................. a camera to take photo 

1. They will open a new restaurant next month

-> A new restaurant......................... next month

2. Mary doesn't have a library card, so she can't borrow books from the library

-> If Mary had a library card,...................... borrow books from the library