连词成句。

l. down walk They street the (.)

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2. many are cars There too (.)

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3. do now he What does (?)

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4. car in men There many the are (.)

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5. men playing These are cards (.)

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质量控制统计数据中( )的大小，反映了工程质量的稳定程度。

A．平均值

B．中位数

C．标准偏差

D．极差