Bears often hide themselves in places __________ can’t be found by hunters.

We should try every effort to prevent violence from happening at school, ______ more and more students would drop out of school ______ their personal safety could not be guaranteed

Who is _______ man in a black hat—It’s Jim Brown. We often play _______ basketball together.

I’m sleepy. I prefer __________ at home to going outfor a walk.

What a pity! I missed meeting my boss at the airport because my car was _____ in the traffic jam.