The English in this story has been simplified to make it easier .
A. to be understood
B. understood
C. understanding
D. to understand
网友回答
A. to be understood
B. understood
C. understanding
(答案→)D. to understand
解析：句意：在这个故事中英语被简化了为了使它更容易理解，题中的结构make it easier to understand, it做形式宾语，真正的宾语为不定式to understand，所以选D。