求助Prep（2.5考试，急！）

首先谢谢各位能给我及时地答复阿，本人2，5号考试，可是Prep还没有看完，真寒阿！大家帮我看看这道题

26.   (25911-!-item-!-188;#058&002160)

The investigations of many psychologists and anthropologists support the generalization of there being little that is a significant difference in the underlying mental processes manifested by people from different cultures.

(A) of there being little that is a significant difference

(B) of there being little that is significantly different

(C) of little that is significantly different

(D) that there is little that is significantly different

(E) that there is little of significant differences

答案为什么选D呢，里面出现了两个that there is little that , 这两个 that分别是做什么成分呢，我怎么读起来这么别扭阿， 谢谢答复：）