—I rang you at about nine, but there was no reply.
—Oh, that was probably__________I was seeing the doctor.
| A．why | B．when | C．what | D．that |
--- 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 |
______ really makes “Gangnam Style” popular is not the lyrics, but the part of “Horse Riding Dance”.
| A．What | B．That | C．Where | D．When |
Tony ________ for the company as an engineer for two decades. Now he teaches mechanics in Peking University.
| A．has worked | B．worked | C．is working | D．had worked |