How long does it         to do homework every day?

His mother is ill. He has to ________ her at home.

The teacher encourages us to          discussions at the English corner.

—I think it’s very dangerous to drive six hours without a rest.
—I agree. Six hours           really a very long time.

Because the old people ________ about thirty percent of the population, we should care more about them.

— What do you think of this book?
— Good indeed. It ________ many problems we have  in our study.

— Where are your parents?   — They ____ Shanghai. They will be back in two days.

---What color_____ the cats?
---I think ________white and black.

Linda,with her friends, ______at the computer room.

Ann likes _______,and she ______ well.