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- Radioactive elements are at the normal background level, causing no deleterious pollution. 环境辐射在正常范围之内，不存在任何人为造成的放射性污染。
- Radioactive elements are at the normal background level,causing no deleterious pollution. 环境辐射在正常范围之内，不存在任何人为造成的放射性污染。
- The distance at which the magnetic field from the line becomes indistinguishable from typical background levels differs for different types of lines. 要使输电线产生的电磁场辐射等级和典型的背景电磁辐射等级差不多，这个距离得随输电线的不同而变化。
- A Study on the Selenium Background Level in the Soils in Guizhou 贵州省土壤硒的背景值研究
- He has a strong political background. 他有强大的政治背景。
- That incessant background music gets on my nerves. 那没完没了的背景音乐令我非常烦恼！
- Business bounced back to prewar levels. 商业回升到战前的水平。
- He has a working-class background. 他是工人阶级出身。
- Get the fall in the background, will you? 把瀑布拍进背景中去好吗？
- A background accompaniment, as for a performer. 伴奏为一个演奏者配音伴奏
- Interest rates are running at record levels. 利率达到创记录的水平。
- She came from a privileged background. 她出身於特权阶层。
- In this period, unemployment reaches record levels. 这段时间的失业人数又达到了创纪录水平。
- He came from an impoverished background. 他出身贫寒。
- The ground levels off beyond those houses. 这些房子那边的地变得平坦了。
- This book gives the background of the Civil War. 这本书叙述了南北战争的背景。
- We must increase production levels. 我们必须提高生产水平。
- Other motives may have lurked in the background. 这后面可能隐藏着其它动机。
- Radiation reached unheard-of levels. 辐射作用已达到前所未有的程度。
- He was lurking slyly in the background. 他狡猾地躲在背後活动。
