It's very foolish of the commander to expose his men to unnecessary risks.
这个指挥官让士兵们冒不必要的危险真是太愚蠢了。
You shouldn't expose the soldiers to unnecessary risks.
你不应该让士兵们冒不必要的危险。
The reporter was killed because he tried to expose a plot.
这名记者因为试图揭露一个阴谋而被杀害。