Calder used his engineering knowledge to create his first mobiles.

Calder使用了工程学知识来创造他的第一个活动雕塑。

But for all their engineering knowledge, they knew far less about the ground they stood on.

但是就他们所有的工程知识而言，他们对自己所站在的地面所知甚少。

You need not only computer science and engineering knowledge, but also an understanding of psychology and visual design to create a better product.

你不仅需要计算机科学和工程知识，还需要对心理学和视觉设计有所理解，才能创造出更好的产品。