1. I .................... come to the party because I have a lot of work to do.

2. I advise them to economise on petrol. They .................... economise on petrol.

3. You .................... ask him personal questions. It is not a good ide to do it.

4. We .................... leave your things here. It is not allowed.

5. It is possible that the parcel will arrive next week. The parcel .................... arrive next week.

6. Tom hasn't got any friends. He .................... be very lonely.

7. Her neighbour has three big factories. He .................... be extremely rich.

8. It is a good idea to arrive one hour before the departure of the plane. You .................... to arrive one hour before the plane takes off.

9. It is not a good idea to leave the window open. You .................... leave it open when you are not at home.

10. Some mushrooms .................... be poisonous so don't pick the ones which you do not know.