说服教育不是万能的，对依法当罚的违法者，要依法分别给予（）等处罚。否则，不能严肃法纪，不能教育本人和他人，也就无法维持正常的社会秩序。

A.警告

B.罚款

C.行政拘留

D.记过

I can think of many cases ________ students obviously knew a lot of English words and expressions

but couldn't write a good essay. [ ]

A. why  

B. which

C. as  

D. where