He found it hard to ________ the difference between the twins.

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The baby wanted to sleep, so the mother ________ it.

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They will ________ come here on foot.

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Advanced technology made it ________ for people far from you to talk with you face to face.

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Is it ________ for a weather satellite to provide us with weather information we need?

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If a rocket can't ________ speed of 28,440 km/h, it will fall back to the earth.

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The moon is a natural satellite ________.

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Can you ________ the differences between American English and British English?

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We had to close the door to ________ the cold out of the house.

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Li Ming is ________ to ask for help from them.

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