<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>
The answer is C.
Organism, population, community, ecosystem, biosphere
Mars is just a fraction the size of the Earth, so it cooled more rapidly. And as it cooled, its molten iron core hardened. As a result, Mars stopped generating its magnetic shield. And, according to one theory, this left its atmosphere to be scoured away by the solar wind.
Fossils are found of giraffes with short necks.
Lamarck believed the giraffes stretched their necks and passed it to their offspring
necks grew longer due to stretching.
giraffes need long necks for food and evolution provided it to them