The policeman _______ the facts again and again, but couldn’t piece them together.
| A．got through | B．picked up | C．went over | D．turned over |
We should consider the students’ request________ the school library should provide more books on popular science.
| A．that | B．when | C．which | D．where |
He was heard________ three songs in the next room.
| A．sing | B．to sing | C．singing | D．sung |
-Young man, come off the grass; we forbid________ on the grass here.
-Sorry, I didn’t notice it.
| A．to stepping | B．stepping | C．why | D．which |
Christina wasn’t saying anything, but the professor smiled at her _______she had done something very clever.
| A．as if | B．now that | C．while | D．though |
No matter what I do, my efforts ________always end in failure.
| A．lose weight | B．to lose weight | C．losing weight | D．lost weight |