题目

阅读理解。 As we all know, bikes are mainly made of steel(钢材). But can you imagine that they can be made of bamboo? Do you want to know how a bamboo bike is produced? Do you want to make your own bike with bamboo? You can do it at the Bamboo Bike Studio(工作室) in New York. People there can teach you how to make your own bamboo bike. The studio is also helping build factories in Ghana(加纳), which is a country in western Africa. The factories will make cheap bamboo bikes. Bamboo is as good as steel for building a good bike. Marty Odlin works at the studio. He says a bambo14．由Mg、Fe、CuO组成的混合物加入适量的盐酸，充分反应后铁有剩余，则该溶液中含有的金属阳离子是（　　）A．Mg2+和Fe2+B．Mg2+ Fe2+和Cu2+C．Mg2+和Cu2+D．Fe2+和Cu2+