. She is a kind-hearted woman and often has mercy people who are in trouble.A. a; onB. \

问题补充：

. She is a kind-hearted woman and often has mercy people who are in trouble.

A. a; on

B. \; on

C. a; o

D. \; to

答案：

A. a; on

(答案→)B. \; on

C. a; o

D. \; to

解析：考查介词，短语：对某人表示仁慈 have mercy on sb ，句意：她是一个好心的女人经常对那些陷在困境中的人们表示仁慈。所以选B。