问题补充：
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
答案：
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：可联系答.案.网客服索取。
