Answer:
The nervous system helps all the parts of the body to communicate with each other. It also reacts to changes both outside and inside the body. The nervous system uses both electrical and chemical means to send and receive messages.
Explanation:
<span>If I were attempting to date a rock sample that I suspect to be incredibly old, i would use radioactive isotopes with a long half life. When dating rocks and fossils to discover approximately how old they are, radioisotope dating is used on igneous rocks found near fossils. Things like Uranium 235, which is an unstable radioactive isotope of elements, decays at a constant rate over time so can be useful in determining age.</span>
2.) occasionally beneficial
3.) omission of information
4.) addition of information
5.) mistakes in copying
