Today's knowledge of fossil ages comes primarily from radiometric dating, also known as radioactive dating. Radiometric dating relies on the properties of isotopes. These are chemical elements.','.
Answer: Truman announces that he is ordering U.S. air and naval forces to South Korea to aid the democratic nation in repulsing an invasion by communist North Korea. The country was split along the 38th parallel, with Soviet forces occupying the northern zone and Americans stationed in the south.
