Could I hang out with my friends-___. You have to prepare for your math test.

Students can easily fall behind in their studies ____ they don’t manage their spare time carefully

Can I use the telephone on the table, sir?一 Under no circumstances ____to use the telephone in the office for personal affairs.

It’s almost eight years we saw each other last time.

The sportsman ________ save a drowning boy that afternoon;the boy’s parents appreciated him very much.[ ]