—__________ do you exercise?
—Every day.
| A．How many | B．How much |
| C．How often | D．How long |
______ the work is difficult, all the workers are keeping on working .
| A．But | B．Although | C．And | D．So |
Tom often makes his brother____ but yesterday he was made____ by his brother.
| A．cry; to cry | B．to cry; cry |
| C．cry; cry | D．to cry; to cry |
---May we go home mow ?
--- No, you____. You____ to go home until 5 o’clock.
| A．mustn’t; are allowed |
| B．don’t have to; are supposed |
| C．needn’t; aren’t allowed |
| D．can’t; aren't supposed |
He _____in Xinxiang for five years when I heard his news.
| A．has lived | B．had lived |
| C．is living | D．has been lived |
We all should make a contribution to ______ our environment.
| A．protects | B．to protect |
| C．protecting | D．protect |