—Jack, you erase the blackboard today,______?
—But I erased it yesterday.
| A．have you | B．will you | C．didn’t you | D．don’t you |
Long ago, man used to ______ with his hands but now man is used to ______ with machines, and sometimes a robot is used to ___ instead of people.
| A．work, working, work | B．work, working, working |
| C．working, work, working | D．working, work, work |
There is no need ______ because Mr. Smith is still sleeping.
| A．hurry | B．hurrying | C．to hurry | D．hurried |
Mr Smith, _____ of the _____ speech, started to read a novel.
| A．tired; boring | B．tiring; bored | C．tired; bored | D．tiring; boring |
She thought I was praising her son, _____ as a matter of fact, I was scolding him for his bad behavior at school.
| A．while | B．therefore | C．which | D．so that |
The wreckage of something like a jet plain discovered in the heart of the desert is believed ______ a UFO and _______down for reasons still mysterious.
| A．to be; have fallen | B．to have been; to have fallen |
| C．to be; to fall | D．having been; having fallen |