arduous

Building the Great Wall of China was an arduous task that took many generations to complete.

(Chinese) 修筑万里长城是一项艰巨的任务，花费了几代人才完成。

After an arduous climb to the mountain peak, the hikers finally enjoyed the beautiful view.

(Chinese) 在费力地爬上山顶后，登山者们终于欣赏到了美丽的风景。