Some children want to challenge themselves by learning a language different from ______ their parents speak at home.

It’s very difficult _____ the child ______the work in time. Let’s go and help him.

Who has made a mess in my room?—Who elseit but your naughty son?

When we got to the top of the hill, the sun __

The United States _______one of the lowest smoking rates －25.5 percent of the population