A graded section of road is 100 metres long and rises 9 metres.
问题描述：
A graded section of road is 100 metres long and rises 9 metres.
What is the grade (slop) of that section of road?
(a) 0.111
(b) 0.09
(c) 0.9
(d) 1.9 求达人详解
答
一条路长100m高9m,求斜率（这句话不是这么翻译的,但是意思就是这样）
蛮简单的,选B