We had to trek slowly with heavy backpacks through the rugged mountain trail.

trek 是动词，意思是"长途跋涉、徒步旅行"，特指在野外或崎岖地形中缓慢而艰苦地行走。这个词源自南非荷兰语，现在广泛用于描述需要体力的户外徒步活动。