. — Why does the Lake smell terrible?
—Because large quantities of water______.
| A．has polluted | B．have been polluted |
| C．has been polluted | D．is being polluted |
_______Wale_______at school，he would gain much higher a salary.
| A．Had;worked | B．If;worked |
| C．Did;work | D．If;has worked |
She tried to_______laughing，but it didn’t work;the performer gave her an angry look at her.
| A．prevent | B．stop from | C．stop | D．keep |
I need_______stamp to complete my collection.Can you give me a hand?
| A．more one | B．a more |
| C．another more | D．one more |
Can you imagine_______such a mean person?
| A．she marrying | B．her to marry |
| C．her marrying | D．that her marrying |
Before taking the action，you’d better_______a plan first.
| A．make out | B．work out | C．take out | D．put out |