1N-COUNT (生物體生長所需的)微量元素 A trace element is a chemical element such as iron or zinc that occurs in very small amounts in living things and is necessary for normal growth and development. (生物體生長所需的)微量元素
2N-COUNT (金屬或其他物質中的)痕量元素,微量元素 A trace element is a very small amount of a chemical element that is found in a metal or other substance. (金屬或其他物質中的)痕量元素,微量元素