I won’t tell the student the answer to the math problem until he ______ on it for more than an hour.
| A．has been working | B．will have worked |
| C．will have been working | D．had worked |
—Can you _________ somewhere tonight?
—Stay at my house if she likes.
| A．give her up | B．bring her up |
| C．put her up | D．pick her up |
As long as we work closely together, we can overcome any difficulty, _________.
| A．however great is it | B．however great it is |
| C．however it is great | D．however it is great |
I don't care how much you earn. _________ is, I think, whether weare happy that really matters.
| A．It | B．Which |
| C．What | D．How |
I was cooking in the kitchen when Dora returned, her face _________with mud and sweat.
| A．covering | B．having covered |
| C．covered | D．to cover |
The factory produced many famous cars, none of _________ shippedto foreign countries.
| A．them | B．which |
| C．it | D．what |