困难挑战英语词组怎么说

困难挑战英语词组可以用 "tough challenge" 或 "difficult challenge" 表示。例如：

The marathon was a tough challenge, but I managed to finish it.
She faced a difficult challenge when she had to learn a new language from scratch.

还有一些其他常用的表达方式：

Herculean task: 很难的任务，比较难以完成
uphill battle: 困难的挑战，需要努力奋斗
mountain to cpmb: 困难的挑战，需要努力奋斗
steep learning curve: 需要付出很大努力学习的挑战

例如：

Finding a cure for cancer is a Herculean task.
Winning the championship will be an uphill battle for our team.
Learning a new instrument is always a mountain to cpmb.
Mastering a new programming language can be a steep learning curve for some people.