6.4 Put the verb into the correct form.

1. was waiting, arrived; 2. were doing; 3. did you go; 4. were driving, happened; 5. took, was not looking; 6. were, did not know, were doing; 7. have not seen, was trying; 8. was walking, heard, was following, was, started; 9. wanted, changed; 10. dropped, was doing, did not break