问题
选择题
I want to know ______ for the class yesterday morning.
A．why did you come late
B．why you came late
C．why do you come late
D．why you come late
答案
答案：B
本题know后跟的是一个宾语从句，用正常顺序，故不选AC，本题有过去的时间昨天上午，从句使用的是过去时，故本题选B。