Answer:
ion even know what this means
Explanation:
The simple answer is that in a battery the chemical reactions that produce the electrical current are produced from materials that are already in the battery itself, whereas in a fuel cell, the reactants, almost always Hydrogen and Oxygen are fed to the cell like an external fuel.
. However, while a battery makes electricity from the energy it has stored inside the battery, a fuel cell makes its electricity from fuel in an external fuel tank This means that while a battery may run dead, a fuel cell will make electricity as long as fuel is supplied. For hydrogen fuel cells, hydrogen is the fuel and it's stored in a tank connected to the fuel cell. When hydrogen in the tank runs low, you refill it, or replace it with a full tank.
Answer: B. providing access to objects that are hard to find
Explanation: A specimen can be simply refered to as a sample of blood, tissue, fluid or a piece of a matter which scientist take or obtain to have a better look (study) at it in a lab.
Specimen collection is the process involved in getting or obtaining these samples for better analysis in a lab. This process help scientist get, obtain or have access to samples or objects that are not easily accessible.
Therefore Specimen collection helps scientist carry out experiment by providing access to objects that are hard to find.
Answer:
cardiovascular
Explanation:
Through vasodilatation or vasoconstriction in the skin heat exchanges with the outside can be regulated. For example during vasodilatation more blood flows, so the tissue will be warmer and more heat will be lost.