According to the school rules, no student _______ go out of school without the permission of the teachers.

— John, do you have any plans for this weekend?— I’m not sure. I _______ go fishing with my uncle.

We will remember what happened _______the afternoon of may 12,2008.

—The similarities between social networks are striking.—That ________ come as no surprise，because they are all products of the Internet. 

His work _____ have been completed; otherwise, he wouldn’t be enjoying himself on the beach.