问题补充：
---Can you let me know yesterday?
---Because the traffic was bad.
A. why did you come late
B. why you came late
C. why do you come late
D. why you come late
答案：
A. why did you come late
(答案→)B. why you came late
C. why do you come late
D. why you come late
解析：本题考查的是特殊疑问句作为宾语从句，要用陈述句语序，同时要注意时态一致，故选B
