The main copper minerals are malachite, chrysocolla, little chalcopyrite, chalcosine and even little bornite and covellite.矿石主要含铜矿物为孔雀石 、 硅孔雀石, 少量的黄铜矿 、 辉铜矿及极少量的斑铜矿和铜蓝等....
马克思回信给恩格斯说,他的赞誉对自己的鼓励很大.Marx wrote back to say that Engels'praise had greatly encouraged him.马克思和恩格斯科学地预言了资本主义的灭亡.Marx and Engels scientifically forecast the collapse of capitalism.恩格斯懂好几门外国语, 例如英语 、 法语和意大利语.Engels ...