That led to a series of mistaken assumptions about why people become homeless and what they need.

这导致了关于人们无家可归的原因和他们需要什么方面的一系列错误假设。

youdao

You also need to ascertain why they need your product; for what specific purpose, under what circumstances, and why would they choose yours?

你还需要弄清为什么他们需要你的产品；为了什么特殊的目的，在什么情况下，还有为什么他们会选择你的产品？

youdao

They might look funny, but goggles do serious work! Why do people need to wear goggles?

护目镜看起来可能很滑稽，但确实能发挥重要作用！为什么人们需要戴护目镜？

youdao

"If mistakes were made we need to know who made them and why they were made,".

VOA: standard.2009.06.15

All of that means we need to explain why these folks do what they end up doing, and we have some hints, but of course we do not know with any certainty or any confidence.

综上所述,我们来想想为什么这些人,要背井离乡呢,我们有一些线索,但是我们并没有有力的证据

耶鲁公开课 - 古希腊历史简介课程节选

one important argument was,or really family of arguments was, you need to believe in souls in order to explain why bodies are animated, why people are rational,how they can have personalities, how they can be creative,and so forth.

一个或一系列很重要的说法就是，要相信灵魂的存在才能解释身体的活动，为什么人会有理性和人格，为什么有创造力，诸如此类。

耶鲁公开课 - 死亡课程节选

However, when I ask why they need a faster computer and they tell me that it will allow them to build a more valuable deliverable for our clients, the elements of that improved deliverable become part of my strategic vision.

FORBES: CEO 101: Vision, Team Builder, Top Salesman

Why did they need these big bailouts, and they paid them back almost immediately?

WHITEHOUSE: Press Briefing

They need to explain why they would be nothing to make -- doing nothing to solve some of these problems that have been plaguing America for years now, decades.

WHITEHOUSE: Rebuilding the Economy, Creating New Jobs