I. Supply the correct form of the word in brackets.

1. "There's no point in (arrive) half an hour early. We'd only have (wait)." "I don't mind (wait). It's better (be) too early than too late."

2. I always try (come) in quietly but they always hear me (go) upstairs. It's impossible (climb) an old wooden staircase at night without (make) a noise.

3. He may (telephone) while we were out.

4. If a thing is worth (do) at all it is worth (do) well.

5. People used (make) fire by (rub) two sticks together.

6. "My watch keep (stop)." "Because you keep (forget) (wind) it up."

7. Would you mind (show) me how (work) the lift?

8. Your windows need (clean). Would you like me (do) them for you?

9. If you can't turn the key try (put) some oil in the lock.

10. He knew he wasn't the first (arrive), for he saw smoke (rise) from the chimney.

11. I didn't know how (get) to your house so I stopped (ask) the way.

12. This book tells you how (win) at games without actually (cheat).

13. The snow kept (fall) and the workmen (grow) tired of (try) (keep) the roads clean.

14. He postponed (make) a decision till it was too late (do) anything.

15. If you slept under a mosquito net you (not bite) so often.