"All of this is contributing to an underground, sort of 'black' economy, which is very difficult for any of us to measure and gauge.

VOA: standard.2010.06.17

And scientists have been working on this for years and there's been progress, but it's still a very difficult challenge.

科学家们对此已经研究很久了,并取得了进展,但仍有很大挑战

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

This is very difficult because there are no high ladders and pressures from day-to-day work you get very much in the way of learning.

这很困难,因为学习不能一步登天,而巨大的工作压力,还存在于学习的每一天。

麻省理工公开课 - 媒体、教育、市场课程节选

"So,I think this is a normal hiccup in a very difficult process.

VOA: standard.2009.10.26

There's also an important and, I think, a very real sense in which Milton wanted to make it seem and obviously this is a much more difficult feat wanted to make it seem as if the Nativity Ode were the first poem that anyone had written.

我还有一种强烈的感觉,弥尔顿想让人觉得,显然这很困难,想使《圣诞清晨歌》看上去像,任何一个人写的第一首诗。

耶鲁公开课 - 弥尔顿课程节选

"We were here before a couple of times and I made the reservation at the Red Lion Inn about a year ago because I knew it would be very difficult this weekend when I heard about the festival.

VOA: standard.2009.12.25

Internet industry was in a very difficult time at that time, at that period, and we gradually realized that this company cannot really survive if we stick with the backend technology providers thing.

当时互联网行业正处于困境，如果坚持做后台搜索技术提供商,这个公司将无法生存。

斯坦福公开课 - 百度CEO李彦宏演讲：全球最大搜索引擎的发展课程节选

A boy who's bullied by his father may hate his father and want to hurt him but since this would--this is very shameful and difficult.

屈于父亲权威下的男孩,可能会憎恨他的父亲，想要伤害父亲,但这个想法是可耻的，也是难以实现的。

耶鲁公开课 - 心理学导论课程节选

Some of this material for some of you is going to be very,very difficult.

其中一些内容对一些人来说将会非常难。

耶鲁公开课 - 死亡课程节选

But then also a little bit about your history, where you come from, some of your experiences which have helped you or informed your opinions on this very difficult issue that the entire world really is spending a lot of time trying to work on.

然后再谈谈你们各自的经历，你们从何而来，谈一些你们自己的经历,一些帮助过你们，或形成了你们,就这个复杂问题的观点,这个全世界都在投入大量时间试图解决的问题。

普林斯顿公开课 - 人性课程节选

In fact there's research-- for example, this was done with internists, doctors, who are giving a very difficult, very difficult question connected to a liver problem that an individual patient had.

实际上有这样一项研究-,在内科医生，医生中间进行，向他们提出一个，与肝脏问题有关的很困难的问题,那是一个病人的病症。

哈佛公开课 - 幸福课课程节选

And one reason Bowman believes this is that we have such a difficult time in understanding other peoples and other cultures is that the very idea of defending one's honor has largely been devalued in the modern west.

鲍曼给出了一个理由,正是因为西方社会中,对维护荣誉的观念早已淡化,才导致他们对其他社会群体,和特定文化的不理解。

耶鲁公开课 - 政治哲学导论课程节选

It turns out very difficult to study this in a lab.

事实证明,很难对此进行实验室研究

耶鲁公开课 - 心理学导论课程节选