Something is wrong with my PDA. I'll get it ________.

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I ________ Mr. Black but I don't ________ him.

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A．have heard, hear

B．have known, hear

C．have known about, know

D．have heard, know

Children seldom do as their parents ________ when they grow up.

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The little child was too ________ to hear the end of the long speech.

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We should go to school at 8 o'clock ________ school mornings.

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Students shouldn't be allowed to ________ by 11:00 pm because health is more important than anything else.

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He didn't run ________ to catch the train.

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You should be working ________ lying there in bed.

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Teachers and parents should give some ________ to the children when they are in trouble.

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The prices of the ________ camera go down quickly.

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