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

統治階級掌握著物質生產的手段；無產階級僅有的是他們的勞動力。

In science, the most beautiful moments often come from unexpected results.

Psychology must be purely experimental and analytical.

Technology can be our greatest ally in sustainable forest management if used wisely.

所有事情在被證明為不可能之前都是可能的，甚至不可能的事情也可能只是目前如此。

The best way to find yourself is to lose yourself in the service of others.

Freedom is a heavy load, a great and strange burden for the spirit to undertake.

我什么都不發明，我只是重新發現。