This book will show you can be used in other contexts.
A. how you have observed
B. how what you have observed
C. that you have observed
D. how that you have observed
网友回答
A. how you have observed
(答案→)B. how what you have observed
C. that you have observed
D. how that you have observed
解析： 考查宾语从句。宾语从句中有含有一个主语从句。what you have observed
作宾语从句的主语，句意：这本书展示给你如何把你所观察到的东西应用到其他课文当中。故选B。