The best way to learn mathematics is to do mathematics.
"La memoria es frágil, pero la literatura puede salvarla del olvido."
The boundary between inside and outside is not a line, but a gradient.
Certification schemes are the floor, not the ceiling of responsible forestry practice.
译文:这种无端的愁绪最让人痛苦!不要去倚靠那高高的栏杆,夕阳正缓缓沉落,烟雾笼罩的柳林让人见了肝肠寸断。