The place the bridge is supposed to be built should be the cross-river traffic is the heaviest.
| A．which; where |
| B．at which; which |
| C．at which; where |
| D．which; in which |
This is such a difficult question ______ none of us can answer.
| A．that | B．which | C．as | D．/ |
Everyone in the class is expected to ______ these discussions.
| A．participate | B．participate in | C．take part | D．join |
— Does your brother intend to learn German?
—Yes, he intends _______.
| A．/ | B．to | C．so | D．that |
We must do whatever we can ______ those who are in trouble.
| A．help | B．helping | C．do help | D．to help |
—Have you handed in your schoolwork yet?
—Yes, I have. I guess it ______ now.
| A．has graded | B．is graded | C．is being graded | D．is grading |