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。