螳臂当车（螳臂當車）　

◎ 螳臂当车 tángbì-dāngchē

[overrate oneself as a mantis trying to stop a chariot;kick against the pricks;throw straws against the wind] 螳螂奋举腿臂以阻挡车轮。比喻自不量力,招致失败