The mineral malachite contains the elements copper, hydrogen, carbon, and oxygen.矿物孔雀石包含的元素铜, 氢, 碳和氧.The main copper minerals are malachite, chrysocolla, little chalcopyrite, chalcosine and even little bornite and covell...
Let OC be the bisector of angle AOB.OC为AOB的角平分线.A perpendicular bisector of a chord passes through the centre and bisects the arc.弦的垂直平分线经过圆心,并且平分弦所对的两条弧.The article discusses the determination and quality of angular bis...