—What ________ it be?

—It ________ be a car, for it is not moving. It ________ be a house.

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A．must; mustn't; can

B．can; can; must

C．can; can't; must

D．can; mustn't; must

Readers can ________ quite well without knowing the exact meaning of each word.

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I'll do ________ help you.

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Americans eat ________ vegetables per person today as they did in 1910.

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He is said to ________ to his country because a new president comes to power.

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We don't allow ________ in the office, so we mustn't do it.

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She doesn't speak ________ her friends, but her written work is excellent.

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The director was angry because no one ________ his opinion.

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These engines ________ by hand, but now they are started by electricity.

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________ other young men, he also enjoys pop music.

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