This would be the Yellow River > formerly known as Huang He
Then we have Chang Jiang or Yangtze River. These are the two rivers where the heartland of china would be located.
The treaty that was signed by the countries of Western Europe, along with Canada and the United States, in April of 1949 was C) North Atlantic Treaty Organization (NATO).
The document was signed as a defense mechanism against any enemy external party. The organization's headquarters can be found in Haren, Brussels, Belgium.
Actions that should be preformed by all citizens but are not required by the law are called FUNDAMENTAL DUTIES
Answer:
theories is the only word which fits
