On his way to school, he was _____.
A new problem has arisen: how should they broaden the bridge to ______ the flow of traffic?
My grandma always puts everything in the house ______, so it looks every tidy and neat.
If you ______ succeed, apply yourself to the job after finding the proper ______ to doing it.
—Do you think students’ using mobile phones has any advantages? —______.
Everyone knows that ______ is dangerous to play with fire, but ______ is difficult is to prevent children from playing with fire.