The workers in the Huashan Mountains have to ______rubbish to keep the mountains clean.
| A．turn up | B．pick up | C．mix up | D．give up |
The thieves ran away at once when the burglar alarm(防盗报警器)________．
| A．went away |
| B．went out |
| C．went off |
| D．went through |
—Did you see Mr Smith when you were in France?
—No．When I________France，he________to China．
| A．had arrived in；had gone |
| B．arrived in；has been |
| C．got to；had gone |
| D．had got to；had been |
He told us that he________the letters in the morning．
| A．will post |
| B．have posted |
| C．was posting |
| D．had posted |
By nine o’clock yesterday evening，we________our work．
| A．have finished |
| B．finished |
| C．had finished |
| D．finish |
We________four thousand new words by the end of last year．
| A．learned |
| B．had learned |
| C．have learned |
| D．will learn |