As Will Rogers would have said, "There is no such thing as a free variable."

照片是一种非常糟糕的传达事物实际样子的方式。

可持续林业不是一种选择；它是一种义务。

Ah, make the most of what we yet may spend, Before we too into the Dust descend; Dust into Dust, and under Dust to lie, Sans Wine, sans Song, sans Singer, and—sans End!