We must keep our room clean. Dirt and disease go _____, you know.
There is _________ that her daughter will pass the exam to go abroad to study.
The key _________ the string was put into the door to stop the kite _________.
_________ that he had fallen behind,he tried to work harder.
Plastic and rubber won’t _________ electricity,but copper will.
________ no need for everybody to discuss the problem again since it has already been solved.