朗读下列句子时,停顿正确的是 _____。A. I saw my pen friend’s name / in a newspaper / yesterday afternoon.B. I saw my pen friend's / name in a newspaper / yesterday afternoon.C. I saw my / pen friend^ name in /a newspaper yesterday afternoon.
已知椭圆(a>5)的两个焦点为F1、F2,且|F1F2|=8,弦AB过点F1,则△ABF2的周长为()
对于常数、,“”是“方程的曲线是椭圆”的()条件
有关命题的说法错误的是 ()
已知P ,q,则“非P”是“非q”的()
命题“”的否定是()