1. Listen! I (think) someone (knock) at the door.
$\Rightarrow$ think – is being knocked
2. Up to the present, we (write) almost every
lesson in the book.
$\Rightarrow$ have written
3. The earth
(circle) the sun once every 365 days.
$\Rightarrow$ circles
4. The farmers
(work) in the field at the moment.
$\Rightarrow$ are working
5. How many
times you (see) him since he went to Edinburgh?
$\Rightarrow$ have seen
6. Rivers
usually (flow) to the sea.
$\Rightarrow$ flows
7. Look! The
boy (cry)
$\Rightarrow$ is crying
8. Do you know
that man, who (smoke) there?
$\Rightarrow$ is smoking
9. Mrs. Green
always (go) to work by bus.
$\Rightarrow$ goes
10. We (be)
from French. We (be) there for 20 years.
$\Rightarrow$ are – have been
11. That house
(belong) to Mr. Green.
$\Rightarrow$ belongs
12. Mai (lose)
her dictionary.
$\Rightarrow$ lost
13. I (be)
sorry. I (forget) that girl’s name already.
$\Rightarrow$ am – forgot/have forgotten
14. I (wait)
for the manager for two hours.
$\Rightarrow$ have waited
15. You (ever,
see) a lion?
$\Rightarrow$
have you ever seen…