Answer:
to get, acquire or secure
Some isotopes, however, decay slowly, and several of these are used as geologic clocks. Dating rocks by these radioactive timekeepers is simple in theory, but the laboratory procedures are complex. <span>All methods rely on the fact that certain elements (particularly uranium and potassium) contain a number of different isotopes whose half-life is exactly known and therefore the relative concentrations of these isotopes within a rock or mineral can measure the age.</span>
Scientific Theory change but not thrown away because scientist
continue looking for possibilities and exact proportion to prove such theory,
though it is change because they always conducted hypnosis in every theory and
once it proves something different they conduct another hypothesis for more
actual evidence.
High-residue cover cropping is an adaption of conservation tillage in which a high-biomass cover crop is grown during the winter and is rolled or cut down prior to no-till or strip-till planting in spring.