<span>Carbon dioxide is a colorless and odorless gas that is vital to life on Earth. This naturally occurring chemical compound is made up of a carbon atom covalently double bonded to two oxygen atoms. Carbon dioxide exists in Earth's atmosphere as a trace gas at a concentration of about 0.04 percent by volume. Natural sources include volcanoes, hot springs and geysers, and it is freed from carbonate rocks by dissolution in water and acids. Because carbon dioxide is soluble in water, it occurs naturally in groundwater, rivers and lakes, in ice caps and glaciers and also in seawater. It is present in deposits of petroleum and natural gas.</span>
        
                    
             
        
        
        
The correct answer is A. B might sound like it is right but that has nothing to do with what the question is asking. And C is not correct because under the the temperature is 4 degrees c.  
        
                    
             
        
        
        
Answer:
There are two types of cell membranes. Either open or closed. Open is when other particles can get in or out. Closed is the opposite. 
I hope that helps!
 
        
             
        
        
        
Answer: The correct option is B.
Will genetically modified crops increase profit for farmers?
Explanation:
This is because genetically modified crops are produced to achieve a particular advantage. Genetically modified crops are produced with some traits that are beneficial to Agriculture. Farmers choose genetically modified crops in order to increase yield, and produced crops that are resistant to certain diseases. These genetically modified crops are produced because of the traits that increase crop yield when farmers plant them it will increase the profit of farmers.
 
        
             
        
        
        
<h2>Answer:</h2>
Carbon
<h2>Explanation:</h2>
Carbon is essential part of living organisms. Scientist use carbon isotopes for dating purposes but the problem with carbon isotopes is also limited as Carbon dating only works for objects that are younger than about 50,000 years, and most rocks of interest are older than that