He faces the most horrible possibility of losing his money and credentials, which will reduce himself to a pauper of unknown background.

旅客最可怕的噩梦，是钱和证件一起遗失，沦为来历不明的乞丐。

youdao

This section will be used to discuss the Unknown Contacts and the Per Account Notifications, as well as, some of the other background features provided by the Advanced System Prefs patches.

这个章节将用来讨论未知联系人和通过账号的信息通知，不仅如此，还会有一些高级系统配置系列补丁后台支持功能。

youdao

Self adaptive predictor is used to extract periodic signals with unknown frequencies from wide band random noise background.

自适应预估器能用来提取宽带随机噪声背景中未知频率的周期性信号。

youdao

The Good Schools Guide noted that 12 out of 41 British gold medal-winners educated in the UK attended private school. (A 42nd medal winner's educational background was unknown and a 43rd was schooled in Germany).

BBC: Magazine

But information about ethnic background can also refine descriptions of an unknown person.

BBC: Painting a suspect's portrait with DNA