I think he must be writing his essay at home now, ______?
| A．is he | B．isn’t he | C．do I | D．mustn’t he |
You can’t imagine what difficulty we had _________ home in the snowstorm.
| A．walked | B．walk | C．to walk | D．walking |
. The _______ boy was last seen _______ near the East Lake.
| A．missing; playing | B．missing; play | C．missed; played | D．missed; to play |
Don’t leave the water_______ while you brush your teeth.
| A．run | B．running | C．being run | D．to run |
The salesman scolded the girl caught ______ and let her off.
| A．to have stolen | B．to be stealing | C．to steal | D．stealing |
11. Though I have often heard this song ______, I have never heard you ______ it.
| A．being sung; sang | B．sang; singing | C．sung; sing | D．to be sung; to sing |