Experts say ________ to sunlight for too muchtime will do harm to one’s skin

At the beginning of the school term, our teacher told us that every student should get on with each other ___________.

Although she always stays at home, she knows what’s ______ in the city.

She seldom speaks English after class, for she was afraid __ mistakes __ grammar.

You needn’t take an umbrella.It isn’t going to rain.—Well，I don’t know.It________do.