但光学是不够的，我们必须去理解。

But learning is not enough. We must also understand.

youdao

我们必须要重视并理解如何更好地运用2维图形(剪影)去表达自己的想法。

We must focus on understanding how to best use 2 dimensional shapes to express ideas.

youdao

这是非常重要的，空间技术的有些部分你必须去验证，我们向你展示那条途径，另一方面，如果你扩展知识，你可以理解我们在这个教学中所解释的。

This is important and part of the space technology. You have to experiment; we show you the way. On the other hand, if you extend the knowledge, you can understand as we explained in this teaching.

youdao