He said he would come back in a week. A. when B. whatC. that D. why

问题补充：

He said he would come back in a week.

A. when

B. what

C. that

D. why

答案：

A. when

B. what

(答案→)C. that

D. why

解析：when什么时候;what 什么;that那个,引导宾语从句只起引导作用,无意义;why为什么.句意;他说他会在一周后回来.结合语境可知本句宾语从句中不缺少句子成分,故选C.