A:x﹣4×2
B:2(x﹣4)
C:2x﹣4
D:2(x+4)
如图,在Rt△ABC中,∠ABC=90°,BD⊥AC于D,求证:AB2=AD•AC,BD2=AD•DC.
Jim, you can me, but can't me in class.
下列港口中分布在北冰洋沿岸并且为不冻港的是( )