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》

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

This is not easy - these are difficult, difficult judgments.

BBC: Welfare Reform Bill: Part two

His experience shows how difficult it is to create an easy-to-use personal health record that will allow patients to control all their health information online.

FORBES: Why Your E-Health Records Need First Aid

It comes in three main forms, of which two are easy and opportunistic, and one is difficult and far-reaching.

ECONOMIST: Asian companies and the China challenge