Children aged 3-11 years have cotinine levels (a biological marker for secondhand smoke exposure) more than twice as high as nonsmoking adults.是什么意思_Children aged 3-11 years have cotinine levels (a biological marker for secondhand smoke exposure) more than twice as high as nonsmoking adults.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句