It's moving to see so many strangers can care for each other, ____ ____?
如果点M(3,x)在第一象限,则x的取值范围是____.
如图,在△ABC中,D是边AC上一点,连BD,给出下列条件:①∠ABD=∠ACB;②AB2=AD•AC;③AD•BC=AB•BD;④AB•BC=AC•BD.其中单独能够判定△ABC∽△ADB的个数是( )