A synergy between iron and steel, railroads and coal developed at the beginning of the Second Industrial Revolution. Railroads allowed cheap transportation of materials and products, which in turn led to cheap rails to build more roads. Railroads also benefited from cheap coal for their steam locomotives.
Vasco de Gama was a Portuguese nobleman who left Portugal in 1497, sailed around Africa, and reached India in May 1498
Dog went up the hill and sat on the log
Short grasses that grow naturally on steppes provide grazing for cattle, goats, horses, camels, and sheep. Sometimes steppes are overgrazed, which occurs when there are more animals than the land can support. When the short grasses of the steppe are plowed under for agriculture, the soil can erode very quickly.