我画画不是为了交流，而是为了看。

The only way to learn mathematics is to do mathematics.

Sustainable development is not an option, but a necessity for the coal sector.

If oxen and horses and lions had hands and could paint with their hands and produce works of art as men do, horses would paint the forms of the gods like horses, and oxen like oxen, and they would make their bodies in accordance with the form that each species itself possesses.