4.to be a cog in the machine or to be a cog in the wheel是个无足轻重的小角色
He was sick of working for big organisations and being a small cog in a big machine.他厌倦了为大机构工作, 厌倦了在其中扮演无足轻重的小角色。
Mr Lake was an important cog in the Republican campaign machine.莱克先生是共和党竞选班子中作用重要的小人物。