by accident简单

A thriving summer festival season doesn’t happen by accident; it happens when we all chip in.

繁荣的夏季节庆季不是偶然出现的；只有当我们每个人都出一份力时，它才会出现。

by accident

偶然

Most archaeological sites have been located by means of careful searching, while many others have been discovered by accident.

大多数考古遗址是通过仔细搜寻找到的，而另有许多则是偶然发现的。