Sully works as a geologist in the southwestern united states. he plans to choose an unstable isotope to find the absolute age of a rock sample. which two aspects must he consider before making his choice? two answers 14 points 1 there should be a sufficient amount of the selected isotope in the rock. the isotope should be one that decays at a very fast rate. 2 the isotope must not be found in any neighboring rocks. 3 the half-life of the isotope must be long enough to capture the age of the rock. 4 there should be more than one unstable isotope in the rock.

Which group of chordates does  notpossess true backbones?                 a.  birds      b.  frogs and toads      c.  lampreys      d.  crocodilians

In the practice of science, this type of reasoning is used to develop explanations.

After frida stops exercising, she continues to breathe heavily. what is most likely occurring in her body? heavy breathing during exercise has produced an oxygen surplus in her muscles. this oxygen is being transported to her lungs. this is a result of aerobic respiration. heavy breathing during exercise has produced a carbon dioxide surplus in her muscles. lactate is being transported to her liver. this is a result of aerobic respiration. strenuous exercise has caused her body to be in carbon dioxide debt, and she is breathing hard while lactate is transported to the liver. this is a result of anaerobic respiration. strenuous exercise has caused her body to be in oxygen debt, and she is breathing hard while lactate is transported to the liver. this is a result of anaerobic respiration.