她成为这个部门不可缺少的一分子。

She made herself indispensable to the department.

《牛津词典》

仪式、庆典和节日是每个人类社会不可缺少的组成部分。

Rituals, celebrations, and festivals form an integral part of every human society.

《柯林斯英汉双解大词典》

肥皂是我们生活中不可缺少的东西。

Soap is something we wouldn't want to live without.

youdao

So, the poetry that is part and parcel of the conversation between Dean and Carlo--Carlo's poetry--seeps out of that basement room.

所以，诗歌是迪恩和卡洛的对话中不可缺少的一部分,-卡洛的诗歌--从那间地下室里渗出。

耶鲁公开课 - 1945年后的美国小说课程节选

He's a standard literary device that you see in fables of this period, and later--the kind that you find for example in the fables of Aesop.

它只是当时在传说中，不可缺少的角色，你可以在随后的伊索寓言中，找到类似的例子。

耶鲁公开课 - 旧约导论课程节选

What has changed and what has remained essential?

有什么变了，又有什么还是不可缺少的？

普林斯顿公开课 - 人性课程节选