Chia động từ:
1.....you...(be)free next Sunday morning,Mai?
-No.I....(visit)our grandmother.
2.By the time the bus (come)..... this morning,Duong(wait)...... for half an hour.
3.He (work)..... as a research and development chemist 10 years,then he retired.
4.She couldn't get access to the Internet because she (not pay)
...... the bill.
Loga
Sinh Học lớp 12
