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

And in that sense, a lot of my classes are difficult, I have a lot of help on.

虽然有些课程很难，但总能得到很多帮助。

求学热十足的学校 - SpeakingMax英语口语达人

I don't want to have to deal with heat escaping to the outside environment in a way that might be difficult or complicated to measure or calculate.

我可不想处理跑到,环境中去的热量，那测量或,计算起来会非常麻烦和复杂。

麻省理工公开课 - 热力学与动力学课程节选

However, for dietary intake, there have been fewer advances like that because it's such a difficult thing to get a hold of.

然而,对于饮食摄入量,和那些比则进步要少,因为这很难把握

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

If I can just have it there before me, that is a very difficult and derivative intellectual act, and it cannot be understood as primordial or primitive.

仅是面对着它，对于思维来说非常困难，并且这不能被理解为是原始的。

耶鲁公开课 - 文学理论导论课程节选

As you have no doubt experienced, this is a dense and difficult poem, so please reread it innumerable times for Wednesday's class, and in addition to that do the other readings assigned.

你们肯定也觉得了，这首诗很复杂很难懂，所以要一遍一遍的重复读，准备好周三的课，也要读布置的其他材料。

耶鲁公开课 - 弥尔顿课程节选

If we have a small engine, and we have to pull the car up a steep hill,a difficult hill, the engine is more likely to collapse,to blow up.

如果我们用的引擎很小，想把车开上一个陡峭崎岖的山坡，引擎很容易损毁，爆炸。

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

But it's difficult, because you have to go there like four or five times a week.

但是要坚持学习真实太难了，你一周得去四、五次。

I used to实战 - SpeakingMax英语口语达人

It is a little bit difficult in the sense that to have gotten into Princeton, one almost certainly has had to know something about something. Right?

之所以比较困难是因为,一个人如果想要进入普林斯顿大学，他一定,对某个领域有一定了解？

普林斯顿公开课 - 人性课程节选

For most people, that's a difficult concept and-- I think I may have mentioned some of this before, but let me give this history.

这个概念对大多数人来说有些难,我记得我之前提及过其中一些,但还是让我来讲述一下它的历史

耶鲁公开课 - 金融市场课程节选

So we now have a situation that is much more difficult.

以至于现在的局势对于我们来说更加困难了。

普林斯顿公开课 - 国际座谈会课程节选

Imagine how much power it takes to drive an artificial heart, so you've got to have a battery or some way of generating power continuously to operate that and that makes it difficult to think about implantable and so that's a really good example of Biomedical Engineering.

驱动人工心脏所需要的能量是难以想像的,所以需要电池或者是某种持续发电装置,来给人工心脏提供能量,这就增加了人工心脏的植入难度,这是很好的生物医学工程的例子

耶鲁公开课 - 生物医学工程探索课程节选

They are really a difficult concept to grasp when you have no base knowledge of it.

当你没有基础知识时，冠词确实很难掌握。

韩国人经常犯的失误 - SpeakingMax英语口语达人

who, you know, have a very strong, difficult-to-understand accent, then they would say that

他们有很重的、难以听懂的口音，然后他们会说，

优雅的英式英语 - SpeakingMax英语口语达人

If it were all the things that it's not, or if it were identical to all the things that somehow or another it's not, then I would be in a very difficult situation because I wouldn't have any means of knowing it in particular.

如果一件事就是它自身的反面，或者和其他的事物没有区分之处,那么我们，就很难认识它,因为我们没有办法认识它。

耶鲁公开课 - 文学理论导论课程节选

But before we dismiss Aristotle's account as insufferably inegalitarian and elitist, we have to ask a difficult question, not just of Aristotle, but more importantly of ourselves.

但在我们驳斥亚里士多德的论点之前,即令人无法忍受的不平等及精英者论点，我们必需要问一个艰难的问题，不只是关于亚里士多德，对我们更是重要。

耶鲁公开课 - 政治哲学导论课程节选