The railways carry millions of tons of freight every year.铁路每年运送数百万吨的货物。The inefficiency of the distribution system has led to the loss of millions of tons of food.分销系统的低效已经造成数百万吨食品的损失。Millions of tons of slag now go into building roads each year.每年有数百万吨炉渣用于铺路。