A:That trees need
B:These trees need
C:That tree need
D:Trees need
地球自转方向是( )
①(2x+y)2=4x2+y2,②(a﹣3b)2=a2﹣9b2,
③(﹣x﹣y)2=x2﹣2xy+y2,④(x﹣ 12 )2=x2﹣2x+ 14 .
细胞有丝分裂完成后,平均分配到两个子细胞的物质是( )