As students we have to ________ to learn more knowledge.

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--- Dear, we have to find a gas station.

--- Why? Aren't we going to the hotel?

--- But we will soon run ________ gas.

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This is an ________ book, I am ________ in it.

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--- ________ have you been doing your homework?

--- Since 6:30 this evening.

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How long have you ________ the car?

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--- ________ have you been skating?

--- I've been skating for five hours.

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--_________ did you start to play tennis?

--I started to play tennis when I was seven.

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A. When

B. How long

C. What time

Will there be _______ pollution than now?

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He _______ speaking. He often helps us.

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A. is good at

B. gets on

C. makes a living

D. is able to

Human is famous ________ its rice and fish.

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