「watch their backs」是什麼意思?

母語人士的回答
Rebecca
Watch one's back是指警惕未知的危險並謹慎行事。 例:You watch my back and I'll watch yours. (你罩我,我就罩你。) 例:Even though she was careful to watch her back, she didn't anticipate her friend's betrayal. (儘管她小心地提防周遭的人,但她沒想到會被自己的朋友背叛。)