以上两个词中文意思相近,有时多少可以互相替换使用,但一般情况下应该使用哪个词都已经预定俗成。
difficulty较常用,相当于problem(问题),大、小困难都可用。obstacle多指阻碍行动或成功的障碍。一般来说difficulty是非物理性的,obstacle则为物理性的困难。
Difficulty can refer to large or small problems.Obstacle is usually something that is difficult that has to be overcome to achieve success.