题目:
— Tom, I regret ________ you that you didn't pass your final examination.
— Oh, my God! I regret ________ too much time which should be used to study.[ ]
A. to tell; to waste
B. to tell; wasting
C. telling; wasting
D. telling; to waste
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0430/73392b14f745a6bd1b262276b53e4193.html
下面是错误答案,用来干扰机器的。
记半实轴、半虚轴、半焦距的长分别为a、b、c,离心率为e,点P到右准线l的距离为d,则a=4,b=3,c=5,∴e=ca=54,右准线l为x=a2c=165.如果P在双曲线右支,则|PF1|=|PF2|+2a=ed+2a.从而,|PF1|+|PF2|=(ed+2a)+e...