Certain other elements are needed in trace amounts for cell metabolism . 细胞的新陈代谢还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 . 我们现在知道,连我们吃的新鲜食品也含有微量的化学药剂,含量一大,就可能有危险。
Measurement of trace amount phosphorus in potable water 饮用水中痕量磷的检测
Edgar : there were trace amounts found in the animals ' blood 在动物的尸体里发现痕量
Determination of the trace amount of cadmium in edible oil 食用油中痕量镉含量的测定