中纬度是指( )
A:30°~60°
B:23.5°~66.5°
C:0°~30°
D:60°~90°
一个不透明的袋子中有3个红球和2个黄球,这些球除颜色外完全相同.从袋子中随机摸出1个球,这个球是黄球的概率为 ____.
— did you stay in the library?
— I stayed there for over two hours.