Certain other elements are needed in trace amounts for cell metabolism . 細胞的新陳代謝還需某些其它的微量元素。
Even foods that are eaten freshly, we now know, can contain chemicals in trace amounts that could, in large amounts, be dangerous . 我們現(xiàn)在知道,連我們吃的新鮮食品也含有微量的化學(xué)藥劑,含量一大,就可能有危險。
Measurement of trace amount phosphorus in potable water 飲用水中痕量磷的檢測
Edgar : there were trace amounts found in the animals ' blood 在動物的尸體里發(fā)現(xiàn)痕量
Determination of the trace amount of cadmium in edible oil 食用油中痕量鎘含量的測定