Answer:
As agriculture increased, more farming machines were used.
West Siberian Plain, Russian Zapadno-sibirskaya Ravnina, one of the world's largest regions of continuous flatland, central Russia. It occupies an area of nearly 1,200,000 square miles (3,000,000 square km) between the Ural Mountains in the west and the Yenisey River valley in the east.
The answer is A :) Hope I helped <3
Tropical places are hot because the humidity coming from the moisture of the plants and water are heated by the sun on the top layer of the tropical zone. The climate varies little in rain forest. There are five layers in the tropic trees so it's so thick that barely any light come through. This is also why vines grow up the trees so they can reach the sunlight to get nutrients. Also, the tropics are near the equator and that also causes the heat. The polars are cold because they barely get any sun heat to melt the snow or warm it up. The polars are melting due to certain chemicals and gasses in the atmosphere. also known as global warming. Hope that was helpful!
