--Do you know when the Chinese custom_________ from?
--It's hard to say. But its characteristics__________ the Tang Period.
—I’m afraid I can’t go to your party; I have lots of things to do.
—________.
—Bad news?
—If you ______ know, Li Na got defeated again in the first round!
—What time do we have to be at the gate of the museum?
—______ the visitors begin to check in.
---Hello, I’d like to speak to Henry.
---Oh, which _______? There are two ______ in our office.
— Why didn’t they complete the task in time?
— Because it was not until late afternoon _____ they began to solve the major problem.