竭尽心力

Explanation: Exhaust: to do, exhausted. Exhausted all the power. 　　Source: "Three Kingdoms Weizhigukui Biography" Pei Song of the note cited "Wei Brief": "do effort, Feng Xuan Ke law." 　　Examples: Every person no longer so, when the Central Plains from the past students were not well, it would not shrink in the Sky ~ ear. ★ Qing Ji Yun "Notes of the West magazine four Cassia"