Ответ:

  1. I was waiting for a bus when I saw the accident.
  2. What were you doing yesterday at five o’clock?
  3. Have you ever tried Chinese food?
  4. I have never stayed in a hotel.
  5. Dad has made pancakes for dinner.
  6. You mustn’t make a noise. The baby is sleeping.
  7. You must be careful when you cross the street.
  8. You shouldn’t leave your rubbish in the forest.