But the professor says it is difficult to find enough feathers from a single dinosaur to recreate all its colors.

VOA: special.2010.03.16

And so part of the wilderness experience for me I think Mark Twain talks about wilderness and he says, I do it chiefly because it is difficult.

对于我来说，荒野的经验就像是,马克吐温在谈到荒野时所说，因为困难，所以我才去做。

普林斯顿公开课 - 人性课程节选

it's very difficult when one is so articulate and is able to express exactly what you want to say,

当一个人已经熟谙一门语言，能够用这门语言清楚明白地表达意思，

想学好英语吗？ - SpeakingMax英语口语达人

But it is difficult to read and judge a wave when it is near.

VOA: special.2009.03.17

He says that it is difficult to make the distinction.

他说很难区分。

耶鲁公开课 - 文学理论导论课程节选

Even today, it is difficult to walk or ride through the park.

VOA: special.2009.04.15

But I want you guys to think about why it was difficult to do it another way, which is more pedestrian.

但是我希望你们能思考一下,为什么用另一种更普遍的方法来做,反而会比较难呢

耶鲁公开课 - 基础物理课程节选

So it is difficult to see the animals in the sand.

VOA: special.2010.01.04

I worked on specifically, I looked at -and this is also the reason why it's difficult to say what is a just university, because we didn't just look at Princeton, we didn't just look at Ivy League Schools or at least private institutions.

我专门研究的是,顺便，这也是为什么,为公正的大学下定义很难得原因，因为我们研究的不仅仅是普林斯顿大学，也不仅仅是常青藤学校,至少不是私人学校。

普林斯顿公开课 - 人性课程节选

But it is difficult to put a price on troubled securities.

VOA: special.2009.01.30

By "difficult," it is meant, I think, well, first of all that it is in some sense set apart from common speech, as a specialized and highly self-conscious use of language.

艰深“的意思，我认为，首先，某种程度上它是和平时谈话有所不同的，专业性极强，对语言运用自知也很高。

耶鲁公开课 - 现代诗歌课程节选

It is difficult to tell exactly where the saying began.

VOA: special.2010.07.25

Okay. So that's what syncopation is and it isn't much more difficult than that.

好了,这就是切分音,也并非很难理解

耶鲁公开课 - 聆听音乐课程节选

So when you talk to class four, he says,then it is difficult to teach the little kids in class one.

VOA: standard.2010.02.25

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

There is this audit and recount process. It is difficult to put a timeline to both of these activities at this point."

VOA: standard.2009.09.15

In many ways for Aristotle as it is for every student of politics the most serious the most difficult issue one confronts is the problem of faction.

从很多方面看来，无论是对亚里士多德,还是每位政治系的同学而言,最令人最感严肃,与严重的问题,是派系的问题。

耶鲁公开课 - 政治哲学导论课程节选

and we are working with the settlement community to try to ease the pain involved because we know it is difficult for them,".

VOA: standard.2010.01.03

And this is no surprise if what we are is the workings of our physical brains, but it is extremely difficult to explain if one is a dualist.

如果我们的本质就是生理大脑的活动,那这也就没什么可惊奇的,但对于二元论者来说,解释这些却是非常困难的

耶鲁公开课 - 心理学导论课程节选

"I think one needs to recognize given the current state of relations it is difficult to describe it as a strategic one anymore.

VOA: standard.2009.10.27

And I do that very precisely because it'll teach you a little bit about how easy or difficult it is to do it and what kind of information you retrieve from a dietary assessment.

我这样要求是因为,这能教给你,做评估的难易程度,以及你们能从饮食评估中得到何种信息

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

"It is difficult enough when we lose these brave Americans in battles overseas,"

VOA: standard.2009.11.05

So if you're trying to make a more complicated organic molecule carbon-carbon bonds are one of the most difficult things to make in organic chemistry, and it turns out that c n minus is a very reactive molecule, so it's a good way, even though we'll go over some drawbacks in a second, it is a good way to make carbon-carbon bonds.

如果你要合成一个更复杂的有机分子,碳碳键是有机化学中,最难制造的键之一，而实际上氰离子是一种具有很高活性的分子，用它是一个好办法，尽管我们一会儿将看到它的一些缺点，但它的确是一个制造碳碳键的好方法。

麻省理工公开课 - 化学原理课程节选

He says it is difficult to know how the disease will evolve.

VOA: standard.2009.05.14

Now the question is "how does it expand" and "why is it so difficult for us to understand, accept, assimilate and live according to the fact that we can make a difference, if we understand that what we need to understand is how change happens.

问题是“它如何扩大“,以及为什么我们难以理解，我们能够做出改变这个事实,并接受，被同化以及据此生活，如果我们能了解我们需要理解的,是改变如何发生。

哈佛公开课 - 幸福课课程节选

I know it is difficult,". "After all,this is not democratic environment.

VOA: standard.2009.11.01

I want to say a little bit about the cost of vaccines because this is a part of what makes it difficult to accomplish what's usually our goal in a vaccine development, which is deliver the vaccine to every population in the world.

我想谈谈关于疫苗的成本,因为这是令我们的疫苗发展目标,无法得以实现的困难之一,这个目标就是将疫苗送至世界上每一个人

耶鲁公开课 - 生物医学工程探索课程节选

"Because there are only a couple of previous records of eruption at this particular volcano, it is difficult to judge either how long the activity will go on there, or how long the volcano might then be dormant before it goes active again."

VOA: standard.2010.04.15

But a few verses later it's clear that the poet isn't really drowning: this is a metaphor for his difficult situation.

但是随后的几首诗证明了，诗人并没有真正的溺水：,这里的水象征着困境。

耶鲁公开课 - 旧约导论课程节选

But,it's hard,if you're fourty-seven years, your job is a pretender to the throne, it's difficult.He had a hard time getting around.

但是,如果你要花四十七年,去争夺王位,是很不容易的,他做得很艰苦

耶鲁公开课 - 1871年后的法国课程节选