如图,在长方体ABCD﹣A1B1C1D1中,AA1=2AB,AB=BC,则下列结论中正确的是( )
A:BD1∥B1C
B:A1D1∥平面AB1C
C:BD1⊥AC
D:BD1⊥平面AB1C
在地球内部,地震波传播速度最快的地方是( )
----You park here! Look at the sign, it says “No parking”.
----Sorry, I didn't notice that sign just now.
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