You’d better look up the new word in a dictionary____ you don’t know it.

Hurry up.  The car is coming. Wait a minute, Don’t cross the street _____the traffic lights are green. 

 Don’t put your hand out of the car window, ______ you will be hurt by the passing traffic.

I’m not sure if he _____ me . If I ________ , I will go with you.

—How long has John been here? — Two years, _______ he still has no friends.