If you want to work out the problem of stress successfully, you need to find out the _________ first.

Mary didn’t attend the lecture, did she? — Yes, she ______.

Walmart, which is one of the largest Americansupermarket chains, _______ some of its store open 24 hours on Mondays throughSaturdays.

the accident happen in ____ summer— Yes, I remember it happened in ____summer of

Not until I began to work ____ how much timeI had wasted.