The focus on their careers makes them forget about their co-workers, creating a harsh work environment.

focus 在这里是名词，意思是"关注点、焦点"，指把注意力集中在某个特定方面。这个词来自拉丁语，原意是"壁炉、火炉"，引申为"中心点"。 harsh 是形容词，意思是"严厉的、苛刻的"，用来形容环境或条件时表示"严酷的、不舒适的"。这个词来自古英语，与"粗糙、刺耳"的概念相关。