As long as I can remember,________I called,my son would answer.( )
A:before
B:while
C:until
D:any time
一元二次方程x2﹣3x+4=0根的情况是( )
寒冷的冬天,居民楼的玻璃窗上会“出汗”或结“冰花”.下列说法不正确的是( )
.如图,已知△ABC≌△BAD,A和B,C和D分别是对应顶点.如果AB=6cm,BD=7cm,AD=4cm,那么BC的长为( )
下列关于内环境稳态的叙述,不正确的是( )