Vii. use the present perfect or present perfect continuous .
1. i ( write ) three long essays this.
2. he ( work) here since 1990.
3. (you/ever/eat) chinese food?
4. we (not/buy) all our christmas presents yet.
5. can i sit down? i (walk) round the city since early morning. i feel tired.
6. i (not/spend) all my pocket money yet. let's go to the cafe.
7. /clean) all morning?
8. is max ok? he (sleep) since morning.