When it______ air pollution, Beijing faces the three “C” s-----cars，coal and construction，which lead to Beijing's thick air pollution.
| A．refers to | B．comes to | C．happens to | D．speaks to |
The lecturer began by _____ us where the island was, and went on _____ about its
history.
| A．telling；talking | B．to tell；to talk |
| C．telling；to talk | D．he told；talking |
I wondered whether the movie was _____ worth _____.
| A．very；seeing | B．well；being seen |
| C．very；being seen | D．well；seeing |
Besides _____, she is kind and tender.
| A．beautiful | B．being beautiful | C．she beautiful | D．is beautiful |
She admitted _____ the key.
| A．being taking | B．to take | C．having taken | D．to have taken |
I regret _____ you that we are unable to offer you a job.
| A．informing | B．having informed | C．to inform | D．to informing |