To be on the safe side, we should fill up the tank now, because we ______ run out of gas on the way.
All but Tom ___that film before.
“____either you or he to go there?” “_____is.”
____of the land in that district ____covered with trees and grass.
Burning all the lights in the classroom will be a great______ on electric power.
If you build a house with good_______ , it will last long.