He ________every place but found nothing.

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He experimented ________rats.

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

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I've worked with children before, so I know what ________in my new job.

[　　]

Visitors _________not to touch the exhibits.

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It's generally considered unwise to give a child ________ he or she wants.

[　　]

John said he'd been working in the office for an hour, ________ was true.

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The hotel will be the highest building in the city when________.

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A．being completed

B．it will be completed

C．to complete

D．completed

_______is no longer as easy as it once was.

[　　]

A．Choose to eat what

B．Choose what to eat

C．Choosing to eat what

D．Choosing what to eat

You ought to be careful _______ fruit.

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