From his _______expression, we can guess that the problem maybe was quite _______.
| A．puzzled ; puzzling | B．puzzling; puzzled |
| C．puzzled; puzzled | D．puzzling; puzzling |
The reason _______ he was late was _______ he missed the bus.
| A．why, that | B．why, because | C．that, why | D．because, why |
The tiger, once a ____ animal to humans, is now ____ of disappearing on the earth.
| A．dangerous, danger | B．dangerous, in danger |
| C．in danger, in danger | D．danger, in danger |
We shouldn’t spend our money testing so many people, most of ____ are healthy.
| A．that | B．which | C．what | D．whom |
I won’t see the film tonight. I am busy. ______, it is raining cats and dogs.
| A．Beside | B．However | C．Besides | D．As well as |
Computersin offices and homes since 1970s．
| A．have been used | B．had been used | C．was | D．has been used |