Water Cycle is the answer
Since Lithium has one valence electron that means it needs to lose it to form a stable structure. That means it's valence is equal to one. Oxygen has six atoms, in order to form a stable octet structure it needs to accept 2 electrons, therefore it's valence is 2.
Therefore two Lithium atoms bond with one oxygen atom to form Li2O
Idk exactly what you mean but I guess you can ask what kind of cell it has idk?
Water from rain and snow that travels to streams
We have heard about Respiration. In human beings, respiration is a cellular activity which takes place in the presence of oxygen and in result produces carbon dioxide. Jamal model is a clear manifestation of that process. Medulla is the region of a brain that controls the respiration activity. When we breathe we take in oxygen and the excess amount of carbon dioxide is removed from out body.
Brains cells have capability to detect the carbon concentration in blood and add excess amount of carbon from body to the air.