Social relationships are important for setting base for any social system. A society as a whole, variety of families, their particular set of rules and regulations all makes up an ongoing social system. Along with this political structures set up rules for a state or a country as a whole, where society structures end, political structures begin. Simultaneously, economic system is totally necessary to make monetary structure running in the country. Economic system keep money moving along the country just like water moves all the way on earth. Thus all three combine to make an effective social system.
If you're referring to the Great Depression, after the stock market crash, many banks lost money and closed. If you're referring to the recent recession, they lost money and became government-run.
Plants get carbon dioxide from the air. The air contains many gases, including carbon dioxide and oxygen. All organisms need the air to obtain one or both of these gases.
