题目

As the railroads and the highways shaped the American West in the past centuries, a new electrical generating（发电）and transmission（输送）system for the 21stcentury will leave a lasting mark on the West, for better or worse. Much of the real significance of railroads and highways is not in their direct physical effect on the scenery, but in the ways that they affect the surrounding community. The same is true of big solar pants and the power lines that will be laid down to move electricity around. The 19th century saw land grants（政府拨地）offered to railroad compani下列物质中不属于合金的是 [　　] A．球墨铸铁 B．氧化铁 C．不锈钢 D．青铜