Difficult circumstances serve as a textbook of life for people,急用

difficult difficult is not difficult be difficult 翻译difficult difficult是什么意思 difficult反义词 difficult question difficult是什么意思? difficult意思 difficult用法 a difficult Difficult to much difficult 还是more difficult 英语翻译As Economics Professor Ralph Edison says:Undergraduate research can become a valuable part of education.It's a real and valuable privilege.It has to remain an extroordinary undertaking for extroordinary people in extroordinary circumstan English is difficult.(对difficult提问) difficult的比较级是什么?difficult的比较级, a little difficult =kind of difficult difficult colors They are in difficult colors