Cars make our life easier, _________ they bring environment problems. 

---Have you ever heard of Xiao Shenyang? --Yeah. ___ funny person he is! Everyone laughed when they watched his performance.

—Don’t play with the knife, ______ you’ll cut your hand.—Sorry, I _____.

I will never forget the terrible accident _______ it happened so long ago.

 In a position like this, one can ________  stand up _______ lie down . So it is very uncomfortable.