know understand recognize aware区别

我可以告诉你ABD都是没有错误的.这道题很中式化.如果一定要解释,参看朗文现代词典：
aware:if you are aware that a situation exists,you realize or know that it exists
aware和know是一个意思,直接意思是：知道……的存在.但用know是毫无问题的.如果在口语中,用know最好.
understand是理解、了解的意思.比如I understand your feelings.
其宾语也可为一件比较复杂,难以理解的事情.
朗文现代词典提供了类似的例句：
I understand that this treatment may not work.
所以understand也是符合语境的.
recognize:to know who someone is or what something is,because you have seen,heard,experienced,or learned about them in the past
所以recognize是不合适的,准确的中文翻译是“认出、识别出”
出题这道题老师很不负责,他想考aware但是却