色多多在线观看播放-色多多在线观看高清免费-色多多在线观看视频-色多多在线看-欧美aaaaa性bbbbb小妇-欧美aaaav免费大片

The opening up of new markets, foreign or domestic, and the organizational development from the craft shop and factory to such concerns as U.S. Steel illustrate the same process of industrial mutation—if I may use that biological term—that incessantly revolutionizes the economic structure from within, incessantly destroying the old one, incessantly creating a new one.

"The world is a prison, and language is the key."

The only limits you have are the limits you believe.

數學的本質在于它的自由。

技術可以幫助我們監測森林，但拯救它們的是人類的承諾。

可持續化學的未來在于開發在溫和條件下工作的催化劑。