sacrificial lamb
noun [ C usually singular ] uk/ˌsæk.rɪ ˈfɪʃ.əl ˈlæm/ us/ˌsæk.rɪ ˈfɪʃ.əl ˈlæm/
被牺牲的人（或物），牺牲品
someone or something that is given to people in authority and is expected to be harmed or destroyed, especially in order to prevent other people or things from being harmed or destroyed
We knew the department would be a sacrificial lamb when the time came to cut costs. 我们知道，需要减少成本时这个部门将会成为牺牲品。