I think (IM NOT COMPLETELY SURE) its profit incurred on a good or service.
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!
Answer: c) The formation of the ice age glaciers occurred about 21,000 years ago.
Explanation:
The last glacial period occurred in the period between 115,000 - 11,700 years in the past with the recent glacial period called Quaternary glaciation. Though some call this period the last ice age, it is a wrong definition because ice age is defined by year-long ice which still persists in the Antarctica and Greenland. The last glaciation that occurred 21,000 years in the past, is the last glaciation on Rocky Mountain.
It occurred in the period 31,000 - 10,000 years and between 23,500 - 21,000, it was at its highest. The glaciation was not made of the giant ice sheet but was made of mountain glaciers known as Cordilleran Ice Sheets. These sheets produced Lake Missoula which late caused Missoula flooding.