essential mineral

基本解释

Selenium is an essential mineral found in trace amounts throughout the body.
硒是人和动物机体生长发育所必需的微量元素。
Magnesium is an essential mineral for the human body, and is needed for relaxing muscles , bone formation and activating B vitamins.
镁是人体必需的一种矿物质，主要用于放松肌肉，骨形成和激活B族维生素。
Tobacco is an important economic crop, and nitrogen is essential mineral element. Studies on carbon and nitrogenous metabolism of tobacco have important action on tobacco production.
烟草是中国一种重要的经济作物，而氮是植物必需的矿质养分，研究烟草碳氮代谢规律，对指导烟草的生产具有重要的作用。