Science is _____ difficult for some students ____ learn, so many of them don’t like it.
| A．enough, to | B．too, to |
| C．so, to | D．much , to |
It’s our_________/'dju:ti/to study hard.
| A．dollar | B．duty | C．dinner | D．date |
We must _________/kli:n/the classroom every day.
| A．clean | B．clear | C．clever | D．cheap |
How often do you take a shower? I take a shower________/ wins/ a day.
| A．won | B．once | C．win | D．one |
This isn’t my ______/hæ t/.
| A．hit | B．cat | C．hat | D．head |
Sir, you should__________ at the red light．But you didn’t．
| A．stop | B．have stopped | C．not have stopped | D．stopped |