—Thanks for listening to my problem and giving me your advice, Amy.—_________. That’s what friends are for.
Our teacher told us that light _____ much faster than sound.
In our class _____ of the students _____boys.
—_____ you _____ your homework yet?—Yes, I _____ it ten minutes ago.
It’s necessary for you _____ exercise every day.
—Could you tell me _____?—Sorry, I don’t know.