You _ to the meeting this afternoon if you have something important to do.

These shoes aren’t comfortable. You __________ wear them.

(2013·高考新课标全国卷Ⅱ)Since nobody gave him any help，he________have done the research on his own.

If you         smoke, please go outside.

--Would you like to visit Kun Ming by yourself this summer vocation? --I’m not sure. I _____go there with my parents because of the terrible thing at the railway station.