同学你好，该知识点来自沪江网校《零基础直达BEC商务英语高级【职场精英随学班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学你好
arduous
adj.艰苦的；艰难的
例如：
an arduous journey across the Andes
翻越安第斯山脉的艰苦之行
The work was arduous.
这项工作很艰巨。

tough
1. 艰苦的；艰难的；棘手的
a tough childhood
苦难的童年
It was a tough decision to make.
那是个很难作的决定。
He faces the toughest test of his leadership so far.
他面临迄今为止对自己的领导工作最严峻的考验。
It can be tough trying to juggle a career and a family.
要事业家庭两不误，有时会很艰难。
2.严厉的；强硬的；无情的
Don't be too tough on him─he was only trying to help.
别对他要求过严，他只是想帮忙。
It's about time teachers started to get tough with bullies.
现在教师该对横行霸道的学生开始采取严厉措施了。
3.坚强的；健壮的；能吃苦耐劳的；坚韧不拔的
a tough breed of cattle
健壮型的牛
He's not tough enough for a career in sales.
他干推销这一行缺少足够的韧劲。
4.(of a person 人) 彪悍的；粗暴的；粗野的
You think you're so tough, don't you?
你以为自己够厉害的，是不是？
He plays the tough guy in the movie.
他在电影中扮演硬汉。

arduous和tough在表示艰难的时候意思相近，arduous更强调要付出精力和时间所造成的艰辛，除该意思外，tough所具有的含义更多。

祝学习愉快！