解析:设=m,=n,设椭圆的长轴长为2a1,双曲线的实轴长为2a2,|F1F2|=2c,则,由此可得4a12-4c2=4c2-4a22,即a12+a22=2c2.将,代入,选C.答案:C http://59.151.37.108/upres/20091118132318406365.doc
