Steel production growth
1) Between 1900 and 2006, total world steel production (increased / decreased)
2) In 2006, the United States produced (more / less) steel than it did in 1900.
3) In 1900, (north america / asia / europe) had more steel-producing countries than other continents.
4) In 2006, the world’s leading steel producers were located in (north america / asia / europe)