Well, what it is is easily enough explained despite the sort of difficulty and thorniness of the word.

虽然我们遇到过很多困难和挫折,但这个问题很容易解答。

耶鲁公开课 - 文学理论导论课程节选

they were having hard time getting their day- to- day stuff done,

他们在日常生活中遇到了很多的困难，

帮助多文化的家庭 - SpeakingMax英语口语达人

There is a lot of research in psychology, a lot of evidence that shows how difficult change is.

心理学的研究有很多，很多证据显示，改变是非常困难的事。

哈佛公开课 - 幸福课课程节选

There are a lot of human hardships that can be solved by diversifying portfolios.

很多生活上的困难,都可以通过分散投资来解决。

耶鲁公开课 - 金融市场课程节选

There are really two purposes in us doing this: one was so you can get a fix on your own eating, and second you can see the challenges that are involved in assessing what people eat when you start doing studies linking diet to health.

这么做实际上有两个目的,一是你可以调整你自己的饮食,二是当你开始研究,饮食与健康的关系时,你会发现,在对人们吃什么进行评估时存在很多困难

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

He says, "to succeed in many things or many times is 'difficult.' For instance, to repeat the same throw of dice 10,000 times would be impossible; whereas, to make it once or twice is comparatively easy."

他说,要成就很多事情,或成就一件事情很多次,是很困难的,比如,掷一万次骰子都得到同样的结果,是不可能的,但是,掷一两次却是相对容易的

耶鲁公开课 - 金融市场课程节选

Cos I really struggled in high school-- a lot of it was difficult; a lot of it was painful, but it was all worth it.

因为我在高中很努力-,很多时很困难;,很多时很痛苦，但完全值得。

哈佛公开课 - 幸福课课程节选