求解一个结构~~~~

Helloface

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.

(D) that there is little that is significantly different
求解：这里的that is.....是个什么结构？

hermit127

that is, (by way of explanation, clarification, or an example); more accurately: I read the book, that is, I read most of it. Also, that is to say, 但是为什么，前后没有逗号？不确定。。

Helloface

弱弱地问……是引导定语从句么……？