南极洲有世界“寒极” 之称,其酷寒的主要原因是( )①跨经度最广 ②地处高纬度 ③绝大部分被冰雪覆盖 ④受海洋影响大
A:①②
B:①④
C:③④
D:②③
下列说法中,正确的是( )
— is it today?
— It's Monday.
双曲线x2a2-y2b2=1的离心率为62,则它的渐近线方程为( )
一元二次方程(x﹣1)2=0的解为( )
I find difficult for Tom to reach that picture.He is a little short.