Answer:
The correct answer is methane . Nature constitutes most of the substances made up of organic compounds. These compounds have carbon atoms attached with hydrogen atoms with a chemical bond (very few compounds may not have this bond).
D is the answer because the rest ate observations
Answer:
Its internal volume enlarges and the cell membrane expands
Explanation:
Ur digestive system is responsible for breaking down food substances to provide ur body with the nutrients it needs. circulatory system take blood to all parts of ur body.
respiratory system gets oxygen in n carbon dioxide out..your immune keeps you healthy by fighting off infections. and ur excretory system takes out waste fluids out ur body.
you should be breathing, oxygen goes into ur lungs, your blood gets some of that oxygen n Carries it through ur body to keep it working.. now ur body is working, ur digestive system is breaking down food n sending the nutrients into ur blood stream n taking waste materials out n so is ur excretory system.. your immune system is also healthy good because there is no waste substance stuck in ur body thanks to ur excretory system n ur digestive system..now to u see how they r AL connected?..if one fails to do what it's supposed to o, it would affect the other systems...let's say ur respitory system malfunctions...u get no oxygen going in you blood stream which is dangerous because ur circulatory system needs it..or if ur digestive system fails to do its job, u won't be getting the nutrients you need to go in the blood stream n flourish the body, it would affect your immune system..if ur circulatory system doesn't work like it's supposed to be, it would be a bad situation because ur blood could cloth if it stays in a place for too long without moving n u could get a stroke ..blodclothing could stop the flow of blood from going to a location n taking nutrients from the digestive system n oxygen from the respiratory system to that part of ur body n it would feel numb or tingly..n if ur excretory fails, waste substances are traped in ur body which is poisonous n can go into ur bloood stream n affect your immune system..
sorry, this is all in my own words n I wrote a lot..
