那场空难是航空史上最黑暗的一天。

The plane crash was the ___blackest day in aviation history.

这是他有过的最阴暗的想法。

This was his ___blackest thought ever.

这件黑色T恤是我所有衣服中颜色最深的。

This ___blackest T-shirt is the darkest among all my clothes.