教练明确划定了训练强度的红线，任何队员都不能超越。

The coach clearly ___marked the intensity of training that no player should exceed.

这家银行因对低收入社区实行信贷歧视而被起诉。

The bank was sued for ___redlining low-income neighborhoods.

赛车手在最后一个弯道前将引擎转速推到红线。

The racer revved the engine to ___redline before the final corner.