You can refer ________ the notes ________ the text if you don't understand the sentence.

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Do you know the key ________ the problem?

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He didn't tell me the answer ________ the question.

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The old man watched the young boys playing ________ basketball with ________ great interest.

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I was interested ________ in the paper that scientists had found out how to talk to whales.

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East of the lake ______ two villages.

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The incident _______ took place last Monday.

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Nanjing is an old city. which _______ the Chang jiang River.

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Scotland is ______ the north of England; it's ________ of Britain.

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I'm going to the post office.

________ you're there, can you get me some stamps?

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