Fill in the blank

1. If you (have) ___________________ something to eat before, you wouldn't feel sick
now.
2. If Sandy ___________________ (not/eat)so much junk food every day, she could
have been in better shape.
3. If I ___________________ (know) her address, I could have visited her yesterday.
4. If he had a watch, he ___________________ (be) at school on time last Monday
morning.