A system is a group of organs that work together and provide an organism with an advantage for survival. It is the most complex organization in your body and the final level of the progression from cells to tissues to organs and then systems.
Answer:
b
Explanation:
Van leeuwenhoek, hope this is right! good luck!
The process in which the environment<span> selects </span>organisms<span> that will survive is called natural selection. It starts with overproduction; when an </span>organism<span> produces more offpsrings than can survive. The second is variation. Because there are so many offsprings, there will be variations.</span>
It stands for calcium chloride