1. ---, a, a
2. ---, ---, ---
3. ---, a
4. a, the, ---
5. a, the
6. ---, ---, ---
7. ---, the, ---
1. had known .... would have gone
2. would have bought ... had had
3. would have got ... had made
4. would have helped ... had not had
1. must have been
2. must have missed
3. must have known
4. can't have failed