They are talking about the movie they watched yesterdayA. /B. whoseC. whatD. whom

问题补充：

They are talking about the movie they watched yesterday

A. /

B. whose

C. what

D. whom

答案：

(答案→)A. /

B. whose

C. what

D. whom

解析：句意：他们正在谈论他们昨天看的电影。本句中包含有一个定语从句，即they watched yesterday，其先行词为the movie，在定语从句中缺少宾语，故应用关系代词，并可以省略，故选A。