It have been one of difficult problem that pipe intersecting line NC cutting programming in pipe project.

管件类相贯线数控切割编程一直是管道工程的难题之一。

youdao

One problem is that even though the raw materials used in industrial biotechnology may not be derived from fossil fuels, they are still capable of stirring up some difficult ethical questions.

其中的一个问题是，尽管工业生物技术中使用的原材料不来自矿物燃料，但仍会引起难以解决的道德问题。

youdao

This controversy is for good reason: Namespaces solve a difficult problem and are one of many approaches to solving this problem, each of which has its pros and cons.

争议的理由很充分：名称空间解决了一种困难问题，但只是解决这种问题的方法之一，每种方法各有长短。

youdao

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

Each one of these is a difficult problem to unwind, and many of us struggle with more than one.

FORBES: Mailbox App Revolutionizes Gmail Productivity, Will Google (Or Apple) Buy It?

Like all vicious cycles, the relationship between the declining fortunes of news outlets and the shrinking of their audiences is a difficult one to untangle, a chicken-and-egg problem.

FORBES: Pew Study: Americans Abandoning News Outlets, Citing Lower Quality

The new Counter Fraud Service ran into a slight hitch initially: no-one knew just how big the problem was, and without that kind of information it was difficult to demonstrate that anti-fraud work is actually worth the money.

BBC: Hitting back at healthcare graft