过河卒子

Explanation: The rules of chess pawns can only move forward, not backward, over the river can then walk sideways, more powerful. Analogy can only go forward, not backward. 　　Source: Liu Shaotang "smoke signals" can not round rhetoric cheat Erweilaoren home, confused and sweet talk can not Erweilaoren home, so distraught, eyes closed, holding the chest fluttered, lost regret his adventure into the city, but has riding a tiger, only to be a child of the Guohe Cu. "