When different cultures we often pay attention only to the differences .A. compared B. be

问题补充：

When different cultures，we often pay attention only to the differences .

A. compared

B. being compared

C. comparing

D. having compared

答案：

A. compared

B. being compared

(答案→)C. comparing

D. having compared

解析：句意：当我们比较不同的文化，我们经常只注意不同。这是省略句，当主从句的主语一致的时候，可以省略从句的主语和be动词，所以从句的主语是we，而we和compare是主动关系，用现在分词。选C。