You must ________ that the lights are turned off before leaving.

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The young girl has ________ many new designs in computer in recent years.

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I regret ________ that I am unable to go with you.

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I don't believe my grandfather is ________.

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Do you know who is the greatest ________ man?

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His father was the only soldier ________ after the World War Ⅱ.

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We all know that ________ speak louder than words.

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Immediate action must be ________ before it is too late.

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What has happened to you? You ________ pale.

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We shouldn't ________ those slow students at school.

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