题型:判断题 设点p是椭圆x2a2+y2b2=1(a>0,b>0)上一点,F1,F2分别是椭圆的左、右焦点,I为△PF1F2的内心,若 S△IPF1+S△IPF2=2S△IF1F2,则该椭圆的离心率是______. 查看答案
题型:判断题 With all the things he needed _______, he went home happily.A.boughtB.buyingC.to be boughtD.to buy 查看答案