Task 1
A5, B1, C3, D2
Task2
1. must
2. ought to/should
3. don’t need to
4. could
5. am able
6. are able to
7. could
Task 3.
1. should
2.ought to
3. was able to
4. need not
5. was able to
6. must
7. need not
8. must not
Task 4.
1. have you?
2. aren’t there?
3. shall we?
4. will you?/won’t you? возможны оба варианта
5. is there?
6. will you?/won’t you? возможны оба варианта
7. can it?
8. aren’t I?