常見(jiàn)例句雙語(yǔ)例句It is believed that such a level is of no significance to human health having regard to natural background levels.令人信服的是，考慮到自然本底值，這樣小的放射水平對(duì)人體健康是無(wú)關(guān)緊要的。http://dict.hjenglish.comThe results show that the radioactivity level of varied water bod-ies of the city was within normal natural background.調(diào)查結(jié)果表明，上海市各類(lèi)水體中天然放射性核素濃度屬正常本底水平。The results show that the radioactivity level of varied water bodies of the region was within normal natural background.調(diào)查結(jié)果表明，寧夏回族自治區(qū)水體中天然放射性核素濃度屬正常本底水平。 返回 natural background level