n the boy playing by the river fellinto the river, I was out of the room _______

There are a number of methods to provide relief from your toothache, which can’t cure the problem.

Volunteering is becoming more and more popular in the world because it gives us a/an __________ to value (珍惜) what you have, and focus on the truly important things in our life.

There ____some showers tomorrow morning.

’s so cool in the house. You _______have turned on the air-conditioner, haven’t you