harmful trace elements的用法和樣例：
例句
- This "could be due to nonessential, potentially harmful trace elements contained in zinc supplements, such as cadmium, a known carcinogen," the researchers said.
研究人員說，這可能歸因於存在於鋅補充劑中的非必需的潛在有害微量元素，例如致癌物質鎘。 - Results of the project will provide scientific proof for pollution control of trace hazardous elements in the UCG field sites.
項目研究成果為煤地下氣化工程中有害微量元素的污染控制提供了科學依據。
