Researchers were looking for the spectral signature of carbon dioxide when they noticed something baffling: an unexpected wavelength of unknown origin.

在研究人员正在寻找二氧化碳的光谱特征时，他们发现了一个令人疑惑的东西：一道来历不明，令人意外的波长。

One day while Houyi was out on a mission, his wife Chang'e found a strange pill of unknown origin and like any sensible person would do, ate it.

一天，当后羿外出执行任务时，他的妻子嫦娥发现了一种不明来源的奇怪药丸并和任何合乎常理的人一样，吃了它。

One day while Houyi was out on a mission, his wife Chang’e found the strange pill of unknown origin and like any sensible person would do, ate it.

有一天，后羿出差，他的妻子嫦娥发现了一颗来历不明的奇怪药丸，就像任何一个有理智的人都会做的那样，吃了它。

History of travel to an endemic area, and 10) if no obvious cause is found for the fever within 3 weeks in the last case scenario, it becomes known as Pyrexia of unknown origin and requires extensive workup.

疫区旅行史；10）在最后一种情况下，如果在3周内没有发现明显的发烧原因，则称为不明原因发热，需要进行广泛的检查。

Discovered on May 26, 1974 by the Betz family who were surveying damage caused by a brush fire on Fort George Island, Florida, the Betz mystery sphere is a 20.3 centimeter wide orb of unknown origin.

Betz 家族于 1974 年 5 月 26 日在佛罗里达州乔治堡岛调查灌木丛火灾造成的损失时发现了 Betz 神秘球体， 它是一个 20. 3 厘米宽、 来源不明的球体。

The campaign will focus on women and children of unknown origin, in particular vagrants and beggars, women and children with mental health issues or those who are hearing or speech impaired, to ensure they were not trafficked.

公安部要求，要集中摸排一批线索，特别是对来历不明的流浪乞讨、智力障碍、精神疾病、聋哑残疾等妇女儿童要全面摸排，确保底数清、情况明。

As of 21 April 2022, at least 169 cases of acute hepatitis of unknown origin have been reported from 11 countries in the WHO European Region and one country in the WHO Region of the Americas (Figure 1).

截至 2022 年 4 月 21 日，世卫组织欧洲区域的 11 个国家和美洲区域的一个国家至少报告了 169 例不明原因急性肝炎病例（ 图 1） 。