She will tell us why she feels so strongly that each of us has a role ________ in making the earth a better place to live．

A.to have played

B.to play

C.to be played

D.to be playing

答案及解析： B

解析：

本题主要考查了动词不定式的时态与语态。从句意看，整个动作发生在将来，to play作a role的定语，其间存在着逻辑上的动宾关系，又与句中each of us存在着逻辑上的主谓关系，故动词不定式用主动形式表示被动意义，首先排除C项；

动词不定式to play意指将来的动作，to have played意指已经完成的动作，to be playing则强调动词不定式动作正在发生。