Achieving these goals is relatively easy in theory, yet quite difficult in practice.

实现这些目标从理论上说比较容易，但在实践上却相当困难。

《柯林斯英汉双解大词典》

The first question was difficult, but the rest were pretty easy.

第一个问题很难，但其余的都相当简单。

《牛津词典》

I thought the work would be difficult. In actual fact, it's very easy.

我原以为这工作会很难，事实上却很容易。

《牛津词典》

"He knows that this suspension of settlement construction is difficult, that it is not easy for anyone;

VOA: standard.2010.01.03

This is actually a piece of code that is really easy to think about recursively and is much more difficult to think about in other ways.

这确实是一段用递归思考起来非常容易,而其它方法特别麻烦的代码,这一段代码的意思就是。

麻省理工公开课 - 计算机科学及编程导论课程节选

So, he's using intuitive-- he says difficult or easy-- so he says it's difficult, meaning the probability is very low, or easy, meaning that probability is high.

所以他直接进行了描述,他用的是困难和简单两词,他说的困难,意思就是概率很小,他说的简单,意思就是概率很大

耶鲁公开课 - 金融市场课程节选

The process might take a few weeks, depending on how easy or difficult it is for you.

FORBES: How to Master Yourself, Your Unconscious, and the People Around You - 1

The information helps bidders estimate how easy or difficult the transition from TV to their own planned services might be, says Laura Fontaine, a Comsearch director.

FORBES: Peeking Into The Spectrum Auction

Identifying the world's greatest male athlete turned out to be easy to argue but difficult to answer empirically.

WSJ: The World's Greatest Athlete?