This watch needs to be sent to the factory to change the mainspring.

这块手表需要送到工厂更换主发条。

The mainspring for this matter is the lack of common sense among young people.

这件事情的主要原因是年轻人缺乏生活常识。

My mainspring of studying hard comes from my parents' expectations for me.

我努力学习的主要动力来自父母对我的期望。

The mainspring is the most important spring in a watch.

主发条是手表中最重要的发条

My life has been music, and a constant search for it has been the mainspring of my life.

我为音乐而生，对音乐的不懈探索已经成为我生活的动力。

You begin to understand what actions were the mainspring of the story.

你开始明白什么是这个故事的主要情节了。

I think the mainspring is broken.

我想主发条断了。

The love of music was a mainspring of his life.

对音乐的热爱是他一生中的主要部分。

Her jealousy is the mainspring of the novel's plot.

这部小说情节中贯穿了她的忌妒之心。