打边鼓

Explanation: That advocate the sidelines to help. 　　Source: Lu Xun, "the preamble _set_s of _set_": "Just because poetry was lonely, so playing the side drum, collected some fun." 　　Examples: He left Tangzhong Sheng, originally thought he would be in the next ~, to help him persuade the Mamu Han, did not expect Mamu Han to Tang Zhongsheng arrested in the past, fell into a stumbling block. ★ Erfu "Shanghai in the morning," a fourth