Christopher Columbus American

----- Nội dung dịch tự động từ ảnh -----
6. Christopher Columbus American
more than 500 years ago.
a. discovered
b. has discovered
c. had discovered
d. had been discovering
7. I ........ in the room right now.
a. am being
b. was being
c. have been being
d. am
8. I ... . to New York three times this year.
a. have been
b. was
c. were
d. had been
9. Jack . the door.
a. has just opened
b. open
c. have opened
d. opening
10. Almost everyone
... for home by the time we arrived.
a. leave
b. left
c. leaves
d. had left