There __________a pool in the park, but now it is gone.
| A．used to have | B．used to be |
| C．will be | D．must be |
_________trees have been planted near, so the air is very fresh.
| A．Hundreds of | B．Hundred of | C．Two hundreds | D．Hundreds |
The TV play ___________for ten minutes when I turned on the TV.
| A．had started | B．had begun | C．has been on | D．had been on |
The new library building ___________last week.
| A．completed | B．was completed | C．is completed | D．has completed |
The math problem was _________ difficult __________ none of us worked it out.
| A．very; that | B．too; to | C．so; that | D．enough; that |
The CD is too noisy. Would you please__________ a little?
| A．turn it on | B．trun down it | C．turn it up | D．turn it down |