<span>During the twentieth century, absolute date was added to the relative time scale. </span>Geologic time scale uses both relative and absolute dating techniques. <span>Soon after the discovery of radioactivity, geologists used radioactive isotope decay to develop a method for determining absolute ages of rocks</span>
Answer:
what element is all life based on
Explanation:
the element is element carbon
Answer:
External respiration: CO2 diffuses into the blood
Explanation:
External respiration is also called the pulmonary gas exchange. It refers to the diffusion of O2 from the air in the alveoli of the lungs to blood in pulmonary capillaries and diffusion of CO2 in the opposite direction from the capillary blood into the alveolar air. External respiration in the lungs is responsible for oxygenation of deoxygenated blood coming from the right side of the heart. The oxygenated blood is then returned to the left side of the heart.
The answer is <span>b. desert biome </span><span />
1930-1950 hope this helps
