--Do you know when the Chinese custom_________ from?--It's hard to say. But its characteristics__________ the Tang Period.
You’re __ your time trying to persuade him; he’ll never join us.
--Have you finished your report yet? –No, I’ll finish it in ___ ten minutes.
I didn’t see your sister at the meeting.If she ___ , she would have met my brother.
If there were no examinations, we should have ___at school.
---Don’t forget to come to my birthday party tomorrow.--_____.