It is there in case a circuit may not work or water may have entered the circuit they can reset or cut off the switch to get rid of the water.
I'm not sure about number 1 or number 6, but I know that 3 is nucleic acid and 5 is solution.
1) closed circulation
2) The spleen can easily be damaged if someone suffers a sever injury to the stomach. When the spleen is damaged, it can cause pain in the abdomen, dizziness, and pain in the left shoulder.
Explanation:
It should be converting water and carbon dioxide into glucose and oxygen.
