A:
B:
C:
D:
I was told ________ twenty years ago, but it has changed a lot so far.
如图,▱ABCD的对角线AC、BD相交于点O,AE=CF.
如图,已知△ABC中,BC=13cm,AB=10cm,AB边上的中线CD=12cm,则AC的长是( )
①氯化钠②小苏打③生石灰④石灰石⑤碳酸钠