问题

People should open the window in the morning to make air __________ in order to keep the indoor air fresh.[ ]

A: spread
B: remove
C: float
D: circulate

正确答案是：

同类题型

Tom ‘ s brother _____ me_____ Tom just now.

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Can you provide us _________ someinformation _______ the computer

The girl began to cry_____she saw the dog

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