Teaching is useless, 3 | 教學無用 3 | 數學教育 6 | 大世界 7

Intellect is invisible to those have none.

– Arthur Schopenhauer

仁者見仁　智者見智　愚者見愚

— Me@2013-05-21 10:27:27 PM

2013.05.23 Thursday (c) All rights reserved by ACHK