题目内容：

This book will show you ___ can be used in other contexts.A.how you have observed B.how that you have observed
C.that you have observed D.how what you have observed
我不明白为什么要加how

优质解答

这本书可以告诉你,你所观察的怎样运用在别的背景下..
how这里表示怎么运用的意思.what you have observed 整个看作一个整体sth
就可以看成 how sth can be used in other contexts