Hurry up. The car is coming. Wait a minute, Don’t cross the street _____the traffic lights are green.
The flowers in the shop _______, so they _______ well.
-Can you show me _______ to use this kind of camera?-Sorry, I don't know, _______.
The purpose of new inventions is _______ life more difficult, but to make it easier.
-Have you got any books on English grammar? I want to borrow _______.-Yes, here you are. But you must return it by Friday.
-My father with my grandparents _______ Shanghai.-Really? _______ will they come back?