To our surprise, he is always wearing ________.

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Jack is the only one of the students who ________ English well.

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All life on our planet ________ , in one way or another, upon the sun.

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-- I'd like to invite you to a concert this evening.

-- Thank you, but I'm not sure at the moment ________ I'll be free.

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All the things ________ , your plan is practical.

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He used to ________ his teaching when he was young.

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I failed in the final examination last term and only then ______ the importance of studies.

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Reading is an experience quite different from watching TV; there are pictures _________in your mind instead of before your eyes.

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Rather than ________ on a crowded bus, he always prefers ________ a bicycle.

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If water shortage weren't ________ problem in the area, there wouldn't be a need for ________ college graduates.

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