They ______ on the program for almost one week before I joined them, and now we ____ on it as no good results have come out so far.
| A．had been working; are still working | B．had worked; were still working |
| C．have been working; have worked | D．have worked; are still working |
The fact has worried many scientists ______ the earth is becoming warmer and warmer these years.
| A．what | B．which | C．that | D．though |
．He has ______ little education that he finds it impossible for him to equal ______ important a task.
| A．so ;such | B．such ; so | C．so ;so | D．such ; such |
China is playing an important role in the world. That’s Laura has come to study Chinese.
| A．because | B．why | C．how | D．that |
Astronauts in a spaceship have to _______weightless conditions _______are quite different from ______are on the earth.
| A．do with; which; those | B．deal with; that; that |
| C．solve; that; what | D．face; which; these |
— Can you answer my question?
--Sorry, I____________ . Would you repeat that question?
| A．hadn’t listened | B．haven’t listened | C．don’t listen | D．wasn’t listening |