The moment Leo will never forget is Mr. Smith gave him a lot of valuable advice on how t

问题补充：

The moment Leo will never forget is Mr. Smith gave him a lot of valuable advice on how to improve his writing.

A. that; when

B. that; that

C. when; that

D. when; /

答案：

(答案→)A. that; when

B. that; that

C. when; that

D. when; /

解析：考查从句辨析。第一格是定语从句，先行词在定语从句中做宾语，故用关系代词that；第二格是表语从句，由于主语是the moment，所以应用when引导表语从句。