essentialityn.本性；真髓；本质essentialadj.本质的；必要的；重要的n.要素；必需品essential pulmonary hemosiderosis自发性肺含铁血黄素沉积症essentially self adjoint operator本质自伴算子Essential metal elements of human人体必需金属元素Essential public health functions基本公共卫生功能essential oil from dragon juniper龙柏精油essential factors of constitution构成要素essential orthostatic hypotension特发性体位性低血压essential oil of Curcuma wenyujin温莪术油essential isolated singular point本性孤立奇点Essential hypererythropoietinemia原发性高红细胞生成素血症