A:Me too.
B:I'd like some eggs,please.
C:Can I have some eggs,please?
“鲸”人们俗称“鲸鱼”.为什么“鲸”是哺乳动物,而不是“鱼”?
Either Eve or Herb ___________ been invited by Lucy's parents already.
已知斜率为2的直线l双曲线C:x2a2-y2b2=1a>0,b>0交A,B两点,若点P2,1是AB的中点,则C的离心率等于( )
下图是元素X的原子结构示意圈.下列说法正确的是