题干
Was it through Mary,_____ was working at a high school, ____ you got to know Tom?
A：who; who
B：that; which
C：who; that
D：who; which
答案(点此获取答案解析）
C
，对着山峰在平行地面上前进600m后测仰角为原来的2倍，继续在平行地面上前进200
后，测得山峰的仰角为原来的4倍，则该山峰的高度是（ ）