American students take part in a wide variety of after-school activities _______ they develop their social skills.
| A．where | B．which | C．that | D．what |
He hurried to the station only _______ that the train had left.
| A．to find | B．finding | C．found | D．to have found |
The fire made _____ difficult to rescue the people trapped under the ruins in the earthquake.
| A．/ | B．this | C．that | D．it |
--- Would you mind not littering in the classroom?
--- ______. I’ll pick up the waste paper.
| A．With pleasure | B．Thanks |
| C．No, not at all | D．Yes, that’s all right. |
_______ all of them are strong candidates, only one will be chosen for the post.
| A．Since | B．If | C．As | D．While |
______ about the safety of the people in the earthquake-stricken Lushan county in Sichuan Province, Premier Li has flew there to direct the rescue mission.
| A．Concerning | B．Concerned | C．To be concerned | D．Concern |