I find it ________ to learn English well.

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It's difficult to buy the tickets ________ the train during the Spring Festival.

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There are many children ________ in the park.

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________ is good exercise. You should do it every day.

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--Do you often help your mother ________ the windows?

--Yes, I do.

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It's ________ to travel by train than to travel by plane.

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I think it's interesting ________ the train.

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Susan likes the subway because it is easy ________.

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Walking is good ________.

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Mike is riding the bus ________ the library.

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