如履平地

Explanation: Lu: step. The same as walking on level ground. Metaphor of a particular activity is very smooth. 　　Source: Tang Pei 铏 "Zhou Han": "slaves sold by barbarians, or fifteen years, depending on their appearance very cleverness. Articulate into the water, Rulvpingdi." 　　Examples: Jiao Xu Xiang, one of the most courageous, raw little lean, brawn extraordinary, jump Yue Jian, ~. ★ Qing Zeng Pu, "Flower," the thirty-third back