This is not always true-as with the manufacture of pig iron and steel from low-grade iron ores-but it did lead to the concentration of industrial developments on the coal fields.
This is not always true-as with the manufacture of pig iron and steel from low-grade iron ores-but it did lead to the concentration of industrial developments on the coal fields.
并非一概如此—例如从低级铁矿石中生产生铁和钢材的情况一但是这导致了工业发展集中在煤田上。