difficult of难以, 很难
difficultadj.困难的;艰难的;(人)难对付的;不易相处的
difficult medical services看病难
difficulties and hardships艰难困苦
difficult-to-grind ore吐块
difficult and distribution难度分配
difficult-to-cut alloy难加工合金
difficult- pretty events表现难美类项群
difficulties in practicing实践困境
difficult to get along with不好相处
difficulties in development发展难题
difficulties and challenges困难与挑战