September 11 2001 is the day we will never forget.A. thatB. whenC. on whichD. on that

问题补充：

September 11, 2001 is the day we will never forget.

A. that

B. when

C. on which

D. on that

答案：

(答案→)A. that

B. when

C. on which

D. on that

解析：考查从句，从句we will never forget不缺少成份，that引导的同位语从句，句子意思“2001年09.11我们从不会忘记的一天”