问题补充：
---Did you go to school yesterday?
--- Yes, I did. But I was late. When I got to school, Mr. Zhang his lessons.
A. has already begun
B. had already begun
C. has begun yet
D. had begun yet
答案：
A. has already begun
(答案→)B. had already begun
C. has begun yet
D. had begun yet
解析：根据句子表达意思，发生的时态为过去的过去，要用过去完成时，故选答案为B
