Answer:
great oil reserves that encourage economic activities such as oil pro- duction. ... Agriculture plays a smaller role in many countries, such ... leum or natural gas—to make fertilizers, medi- ... duction are important in both Southwest Asia and ... on the earth, producing an even greater strain on water resources
Explanation:
Flammable gas, consisting largely of methane and other hydrocarbons, occurring naturally underground Advantages<span> & Disadvantages of </span>Natural Gas<span>. </span>Natural gas <span>burns cleaner than other fossil fuels, producing half the carbon dioxide as coal and about a third less than oil. It also emits fewer amounts of toxic chemicals like nitrogen oxides and sulfur dioxide.</span>
By size: Russia, China, India
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.