a mantis trying to stop a chariot—overrate oneself and try to hold back an overshelmingly superior force;take no proper measure of oneself
螳臂當(dāng)車(chē)tánɡ bì dānɡ chē
螳臂:螳螂的前腿;當(dāng):阻擋。比喻不自量力。overrate oneself and try to hold back an overwhelmingly superior force, kick against the pricks, throw straws against the wind, mantis shanks to stop a carriage