As is known to all, the newly learnt words will soon be forgotten unless_____ used in everyday communication.

Flight attendants usually need to arrive at the airport ______ before their flight leaves.

“Perhaps we need to send for Dr. Smith to see what we can do about it,” Father suggested ________ to his neighbor who had come to discuss the problem.

The teacher took ____ the lesson where she stopped and finally she set_____ a few minutes to let us discuss it.

The new group of students is better-behaved than the other group who stayed here _____.