There are twenty students in our class, ________ are boys.

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 How much exercise is enough for people each day?

 It's hard to say, because the health condition is different ________.

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A．from area to area

B．from person to person

C．from time to time

D．a great deal

I am sorry to say that you haven't ________ full use of your time.

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They got married and ________ near London.

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Horses live ________ grass.

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Generally ________, women live longer than men.

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He read the book with great attention. ________ he looked up from his book and thought for a while.

[　　]

Do you think it necessary to ________ a few words at the meeting?

[　　]

He had ________ that frequently he felt lonely.

[　　]

I would no longer ________ his advise since it has proved to be of no effect.

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