He is tearing up what he has written _______ and beginning over again.

Playing on a frozen sports field sounds like a lot of fun. Isn’t it risky, ______?

----Leaving for Beijing?    ----_____.

—Do you think it’s a good idea to make friends with your students ? -- ________,I do .I think it’s a great idea .

Most of the evidence was destroyed in the fire. _____, it would be almost impossible to prove Jim guilty.