In 1948，three American scientists invented __________ transistor, which is __________ small electronic device to control an electric current.
| A．the; a | B．a; a |
| C．the; the | D．a; the |
Some countries are increasing their use of natural gas, and other forms of ______.
| A．source | B．energy | C．power | D．strength |
Liping has never gone to Japan, but he speaks Japanese____ he were Japanese.
| A．even if | B．as though | C．even so | D．as long as |
They have decided to ____ the household expenses to devote money to the disaster area.
| A．cut off | B．cut in | C．cut up | D．cut down |
Don't try to cheat in the exam — you will never ____ it.
| A．keep away from | B．go away with | C．get away from | D．get away with |
Regular exercise________our health；that is to say，our health can________it.
| A．benefit； benefit from | B．is of benefit to；benefit from |
| C．is good for；benefit | D．benefits； are benefited from |