重庆市轨道交通二号线高架部分长（）km。
A、15.58
B、16.05
C、16.03
D、15.68
参考答案：C
— Can you describe _____it happened?
— Yes, I was riding on my bike_____ a car knocked me down from behind. [ ]
A. when; as
B. how; as
C. how; when
D. how; while
