17._____ at the gate of the theatre, he found the ticket for the play was left at home.
| A．To arrive | B．On arriving | C．As arriving | D．While arriving |
16.By the end of last year, another new gymnasium _____ in Beijing.
| A．would be completed | B．was being completed |
| C．had been completed | D．has been completed |
15.At the meeting, a proposal that he should take charge of the project _____.
| A．put forward | B．came up | C．came up with | D．Showed |
14.Teachers _____ their knowledge to their students .
| A．pass by | B．pass to | C．pass over | D．pass on |
13.Rainforests _____ and burned at such a speed that they will disappear from the earth in the future.
| A．cut | B．are cut | C．are being cut | D．had been cut |