The chemistry teacher required the students___more attention___the lab clean
| A．to pay;to keep |
| B．to paying;to keeping |
| C．to pay;to keeping |
| D．paying;keeping |
He __________ on the farm for twenty years and now he is a teacher.
| A．has worked |
| B．had worked |
| C．worked |
| D．works |
As a student in Senior Three, I must work hard. __________, I should take exercise to strengthen my body.
| A．Otherwise |
| B．Meanwhile |
| C．Therefore |
| D．Thus |
—Do you think he will do me a favor?
—He is the last one to help others. He __________ give you a hand, though.
| A．might |
| B．must |
| C．can |
| D．should |
The city of Nan Chong has grown so fast that it's at least __________ what it used to be.
| A．five times the size of |
| B．five times the size as large as |
| C．five times larger |
| D．five times size as |
The Greens must have been to 2010 Shanghai Expo, __________ they?
| A．hadn't |
| B．didn't |
| C．can't |
| D．weren't |