天下的根本在于国家,国家的根本在于家庭,家庭的根本在于个人。
估计问题的性质不同。在这里,我们不关心检验特定的假设,而是关心估计参数的值。
In mathematics, the journey of discovery is as important as the destination.
You are easy to pretend to care about.
You are never too old to chase your dreams.
应对恐惧的唯一方法是直面它。