Can you make sure ________ the gold ring?

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A．where has Alice put

B．where had Alice put

C．where Alice has put

D．where Alice had put

I would appreciate it ________ you call back this afternoon for the doctor's appointment.

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Perseverance is a kind of quality－and that's ________ it takes to do anything well.

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Wisdom usually ________ learning and hard work often ________ success.

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Mr Reed made up his mind to devote all he had to ________ some schools for poor children.

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Though they are twin brothers, they are different ________ each other ________ characters.

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One learns a language by making mistakes and ________ them.

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The bell ________ the end of the period rang, ________ our heated discussion.

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A．indicating; interrupting

B．indicated; interrupting

C．indicating; interrupted

D．indicated; interrupted

There are two buildings, ________ stands nearly a hundred feet high.

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Having a trip abroad is certainly good for the old couple, but it remains ________ whether they will enjoy it.

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