a stagnant pool; like a pool of standing water ? 那個(gè)不平凡的舉動(dòng)，使～的清朝政局，激起了一陣波浪。That was a major action agitating the stagnant pool of Qing Dynasty politics.
一潭死水yī tán sǐ shuǐ
潭：深水池。一池子的死水。比喻停滯不前的、死氣沉沉的局面。a pool of stagnant water, stagnant or lifeless condition