—How much the socks?— __ twenty dollars.
—I called you yesterday evening, but nobody answered.—Oh, ______ at that time.
—Do you practice how to escape from dangers every term?—Of course. Our school pays much attention to the ______ of safety.
—Are these books yours, Mike?—No, they aren’t. They belong to ______.
—I think sixteen-year-olds should be allowed to drive.— ______. They aren’t serious enough at that age.
—Let’s visit the sick children in hospital and ______.—OK, let’s go.