They have to be an individual and know that someone will be there to cover for them.
他们不得不成为一个个体，而且知道有人会在那里为他们打掩护。
2
Why would she cover for someone who was trying to kill her?
她为何要包庇那个试图要杀死她的人呢？
《柯林斯英汉双解大词典》
3
Only think of how you behave in private, doing what would cover you in blushes if someone saw you, but because no one else sees you you do it without concern.