森林不需要我们,而是我们需要森林。
从n对观测值的样本中获得的相关系数的可能误差是sqrt((1-r²)/(n-2))。
It is one of the superstitions of the human mind to have imagined that virginity could be a virtue.
如果你不冒险,你永远不知道自己能取得什么成就。
"The best literature challenges us to see the world differently."