加密货币是一种数字形态的货币。他们属于数字资产，可用于购买商品和服务。加密货币也可储存价值、记账和作为交换中介。分布式账本(又称“区块链”)保障了这种数字资产的安全。第一个加密货币是比特币，中本聪(假名)创造了这种加密货币，并在2009年 ...

They are made by heating these chemicals at a high temperature. When the plastic is soft it can be poured into a mould. Once the plastic cools, it hardens into a shape. Plastic is a material that ...