---Could you let me know yesterday ?-Because the traffic was heavy .A. why did you com

问题补充：

---Could you let me know yesterday ?

---Because the traffic was heavy .

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

B. why you came late

C. why do you come late

D. why you come late

解析：考查宾语从句。句意 你能告诉我昨天你为什么迟到吗？因为交通阻塞。Know后面跟着由why引导的宾语从句，用正常语序故排除AC，时间状语是yesterday，故用一般过去时，所以选B 项。