If the firms failed to make enough money,they would______.
| A．close down | B．call off |
| C．turn down | D．set off |
It is often ______ that human beings are naturally equipped to speak.
| A．said | B．to say |
| C．saying | D．being said |
Please don't ______ him. He is quite ______ about his girlfriend's words right now.
| A．disturb; disturbing | B．disturbed; disturbing |
| C．disturb; disturbed | D．disturbing; disturbed |
The drug did not ______ his health. In fact，it seemed to have no ______ at all.
| A．effect; effect | B．effect; affect |
| C．affect; effect | D．affect; affect |
Many young graduates devoted dozens of years to ______ success in life.
| A．seeking | B．searching |
| C．suggesting | D．wondering |
For years scientists have been worried about the ______ of air pollution on the earth's natural conditions.
| A．effect | B．result |
| C．account | D．cause |