Is that the day we’ll never forget.A. thatB. whereC. whenD. on which

问题补充：

Is that the day we’ll never forget.

A. that

B. where

C. when

D. on which

答案：

(答案→)A. that

B. where

C. when

D. on which

解析：句意：我们永远不会忘记这一天。通过分析句子结构，可知这个句子中包含一个定语从句，且关系词在从句中作宾语，故用关系代词that，选A。