Answer:
Human activities contribute to climate change by causing changes in Earth's atmosphere in the amounts of greenhouse gases, aerosols (small particles), and cloudiness. The largest known contribution comes from the burning of fossil fuels, which releases carbon dioxide gas to the atmosphere
Explanation:
 
        
             
        
        
        
Your body may do several things to decrease the amount of water. This includes sweating, urinating, or even vomiting. Too much water could also cause stomach cramps.
        
                    
             
        
        
        
Answer:
The correct answer is eukaryotes engulfed photosynthesizing prokaryotes
Explanation:
The endosymbiotic theory or symbiogenesis is an evolutionary theory that traces the origin of eukaryotic cells from prokaryotic organisms. It explains that some of the organelles (Mitochondria and Chloroplasts) in eukaryotic cells evolved from free-living prokaryotic microbes which were ingested or engulfed. The ingested prokaryotic cells survived within the organism and developed a symbiotic relationship.
According to the theory, chloroplasts was formed when eukaryotes engulfed photosynthesizing prokaryotes and mitochondria was formed when bacteria capable of aerobic respiration were engulfed. 
 
        
             
        
        
        
Answer: Water can hold an unlimited amount of oxygen. 
Explanation:
Water cannot hold an unlimited amount of oxygen because it would get to a point where it is saturated as it needs to hold Hydrogen as well. Air on the other hand, has significantly more space for oxygen as it contains only 21% and can keep taking more. 
Underwater organisms need oxygen for respiration and a small decrease in the oxygen available in water affects aquatic life because they rely on it to survive.