I. Complete the second sentence so that it has a similar meaning to the first.
1. You aren't allowed to make noise in the library.
You mustn't .............................................................
2. It isn't necessary for you to go to school so early.
You don't ................................................................
3. It is a good thing for you to keep the house clean and tidy.
You ought ..............................................................
4. I had a good time at the party last night.
I enjoyed .............................................................
5. Must he leave now?
Does he ............................................................
6. Playing with matches is very dangerous.
It's very dangerous............................................
7. You must stay in bed because of your illness.
You must stay in bed because you ..............................
8. It isn't necessary for you to water that tree every day.
You don't have ......................................................
9. He stays up too late and he is always tired the next morning.
He should go ....................................................
10. It is dangerous to put a knife into an electrical socket.
Putting a knife ...............................................
John has enough money to buy that new bicycle.
17. You ought to keep your house clean and tidy.
18. Mary suggests taking the bus.