用垂直于圆锥轴线的平面截该立体所截得的图形为____。
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棱锥的一个面在W面的投影积聚成一条线,面上的一点A在W面的投影也在这条线上。
A. 对
B. 错
I, who ______ your close friend, will try my best to help you out of trouble. (be)
There _____ a lot of rubbish on the floor so I asked Mary to sweep it up. (be)
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