当知道他有许多敌人时，他开始担心他的性命。 Knowing he had many enemies, he went about in fear of his life.
他在明知他的性命有可能受到威胁的情况下接任了那职位。 He took over the post in the knowledge that it might endanger his life.
她以自我牺牲精神救了我们的性命。 Her self-sacrifice saved our lives.
当然，加强型[防弹]背心价钱昂贵。但是，与穿制服的阿哥阿姐们的性命相较——他们的置一切于不顾日日保护守法的市民——这笔费用应属次要了。 Sure, heavy-duty vests are expensive. But cost has got to be secondary compared to the lives of the uniformed men and women who put everything on the line everyday to protect law-abiding citizens.