设平面π的方程为2x-2y+3=0,以下选项中错误的是(  )。

设平面π的方程为2x-2y+3=0,以下选项中错误的是(  )。 A.平面π的法向量为i-j B.平面π垂直于z轴 C.平面π平行于z轴D.

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设α=i+2j+3k,β=i-3j-2k,与α、β都垂直的单位向量为(  )。

设α=i+2j+3k,β=i-3j-2k,与α、β都垂直的单位向量为(  )。 A. B. C. D.

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Sue's friend knew the way to the police station.

Sue's friend knew the way to the police station. A.Right B.Wrong C.Doesn't Say

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Jack came to the party_______.

Jack came to the party_______.A.without being invited B.without inviting C.wit

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I can't open this door. Can you show me__to open it?

I can't open this door. Can you show me__to open it?A.when B.how C.why

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