I.
7. (-) We haven't eaten too much chocolate.
(?) Have we eaten too much chocolate?
8. (+) I have known David for ten years.
(?) Have you known David for ten years?
II.
1. Has she been late for a meeting?
2. Has he met your family yet?
3. Has she worked in this company for fifteen years?
4. How long has she lived in London?
5. How much coffee have you drunk today?
6. What have you done today?
7. How many books have you read this weekend?
8. Why haven't you brought that?
III.
1. C (yet -> phủ định HTHT)
2. C
3. C
4. B (so far -> HTHT)
5. C
6. D
7. B