I don't know when he . When he , I'll let you know.
| A．will come, will come | B．comes, comes |
| C．will come, comes | D．comes, will come |
—Sir, could you please put out your cigarette? This is a smoke-free (无烟的) school.
—＿＿＿＿＿＿
| A．I'm sorry about this. | B．No problem. |
| C．Sure, I'd love to. | D．Never mind. |
—How often do you chat with your friends online?
—. I'm busy with my study.
| A．Only one month. | B．About twice a month. |
| C．Almost every day. | D．Maybe in two weeks. |
the children have fun, parents can take dance lessons on the beach.
| A．When | B．If | C．While | D．Once |
The World Health Organization has given some advice onto protect us from being infected(感染） with H7N9.
| A．how | B．what | C．where | D．when |
—Linda, I called you this morning, but nobody answered the phone.
—I'm sorry. I football with my friends then.
| A．play | B．played | C．am playing | D．was playing |