She was never willing to leave a problem unfinished, even difficult problems in mathematics.

VOA: special.2009.11.08

It's a difficult problem that not everyone is smart -they vary in their ability -so we try to make a world in which it's pretty safe for the small investor who's not paying attention.

不是所有人都是聪明人,这是个难题,大家能力不同,所以我们试图营造一个环境,一个让小投资者感到安全的环境,而无需忧心忡忡

耶鲁公开课 - 金融市场课程节选

It shouldn't be difficult to see a kind of problem that is beginning to arise in Milton's text here.

这是一个很容易看出的问题,在弥尔顿的作品中也被提了出来。

耶鲁公开课 - 弥尔顿课程节选

Hobrooke admits is a very complicated and difficult problem to address.

VOA: standard.2009.06.15

Well, I talked about the problem of using plasmids in gene therapy, that it's very difficult to get them into cells.

我们之前讨论过,基因治疗中运用质粒的问题,质粒本身极难进入细胞

耶鲁公开课 - 生物医学工程探索课程节选

But for people who have a difficult time controlling their movements, this little navigational issue can be a really big problem.

VOA: special.2011.04.18

Part of the problem with using operant conditioning with babies is it's difficult to get them to behave in any systematic way.

应用操作性条件作用的部分问题在于,很难使婴儿们按照系统的方式行动

耶鲁公开课 - 心理学导论课程节选

Today,the solution to the problem is so common that it is difficult to understand that there was a problem at all.

VOA: special.2010.07.14

I cannot even make it look hard because I have memorized this problem from childhood, so there is no way I can make this look difficult.

我不会让这些问题变得看起来复杂,因为这些问题我童年时就熟记于心,我无法让它变得复杂

耶鲁公开课 - 基础物理课程节选

The most difficult national problem facing the administration of President Franklin Pierce was the situation in Kansas.

VOA: special.2009.05.07

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

"The problem with that body of research is that it's difficult to interpret because obviously people with existing mental health problems use cigarettes to self-medicate."

VOA: standard.2010.06.15

Now, as I said last time, the subject of free will--or free will, determinism, causation and responsibility, this cluster of problems-- is an extremely difficult and complicated physical problem.

正如我上次所说的,自由意志这个主题 或者说自由意志,决定论,因果论,责任,这一堆问题,是极端困难和复杂的物理问题

耶鲁公开课 - 死亡课程节选

There was a conditional agreement: yes, Norway should manage this oil risk but it's politically difficult and that's the problem-- is that we're not able to do our optimal management.

他们在一定程度上同意我的观点：,是的，挪威应该设法解决石油的风险,但这在政治上很困难,其问题在于-,挪威无法做到最优的管理。

耶鲁公开课 - 金融市场课程节选

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