chia các động từ sau ở thì quá khứ đơn và hiện tại hoàn thành
1. I (not see) ................ him last Monday.
2. up to the present, we (write) ............. almost every lesson in the book.
3. How many times ............... you (see) .............. him since he went to Edinburgh?
4. Mary (lose) ............ her hat and she (look) ............. for it until now.
5. I (read) ........ the noved written by Jack London several times before.
6. he (write) ....... a book since last year.
7. Mr Green. (teach) ..... English in this school since he (graduate) ...... from the university in 1986.
8. My father (not smoke) ...... for 5 years.
9. how long .......... Bod and Mary (be) ........ married?
10. she (win) .......... the gold medal in 1986.