Tomorrow I'm flying to Beijing.I there for the following three weeks.( )
am
have been
will be
was
Sam spends two hours _______ his homework every day.
— Watching TV too much _______ bad for your eyes. —I’ll go to bed right away.
Do you prefer _______?
—Mr. Hu, can you tell us how to learn swimming well? —Sure. But remember we can learn nothing well _______ hard work.
I think _______ necessary for you _______ breakfast.