The play had already been on for quite some time when we __ at the New Theatre.
| A．have arrived | B．had arrived | C．arrived | D．arrive |
When he knocked at the door, my mother was busy ____ supper.
| A．preparing for | B．in preparing |
| C．to prepare for | D．to prepare |
He waited until it was dark ____ nobody could see him clearly.
| A．so that | B．in order to | C．although | D．However |
Now there are many _____ in our company.
| A．woman doctor | B．women doctor |
| C．woman doctors | D．women doctors |
We should think of ways to stop the waste from the factory _____ our living environment.
| A．being polluted | B．polluting | C．from being polluted | D．Polluted |
As far as I know, this man ____ risk anything than lose the ring for his wife.
| A．would rather | B．had better | C．preferred | D．would like to |