填空题
A.条件(1)充分,但条件(2)不充分. B.条件(2)充分,但条件(1)不充分. C.条件(1)和(2)单独都不充分,但条件(1)和条件(2)联合起来充分. D.条件(1)充分,条件(2)也充分. E.条件(1)和(2)单独都不充分,条件(1)和条件(2)联合起来也不充分.
△ABC是等腰三角形.() (1)△ABC的三边a,b,c满足(a-b)(c2-a2-b2)=0; (2)△ABC的三边a,b,c满足