The reason for that is because all of this is connected, so we're moving electrons everywhere in the system.

这个现象的原因是因为,它们全部都是连接起来的，所以在这个系统中,电子移动到所有地方。

麻省理工公开课 - 化学原理课程节选

Well, one reason is that there are developmental disorders that seem to involve damage to one system but not to another.

一个原因是,发展障碍看上去,只会对某一个系统产生损害,而不会损害其他系统

耶鲁公开课 - 心理学导论课程节选

The reason for that complexity is because your immune system needs to be able to respond to all the potential foreign invaders that we could encounter.

整个系统之所以如此复杂是因为,免疫系统需要应对所有,我们要面对的来犯之敌

耶鲁公开课 - 生物医学工程探索课程节选