arduous

详细解释:a. 费力的, 努力的, 险峻的

词型变化：

名词:arduousness副词:arduously

英语解释：

形容词 arduous:

characterized by toilsome effort to the point of exhaustion; especially physical effort同义词：backbreaking, grueling, gruelling, hard, heavy, laborious, operose, punishing, toilsome