Mary is a humorous and warm­hearted woman and that is she is a most popular person in

问题补充：

Mary is a humorous and warm­hearted woman and that is she is a most popular person in her community.

A. whether

B. because

C. how

D. why

答案：

A. whether

B. because

C. how

(答案→)D. why

解析：D 考察表语从句。句意：玛丽是一个很幽默而且很热心的人。这就是她为什么成为社区里非常受人欢迎的人。空格处引导的句子是is的表语，表示原因。故D正确。