The situation would be that, in a sealed tube,  there are 3 to 4 nails inside and a certain amount of calcium chloride was added. After three days, there will be no changes to be observed in the first tube since the oxygen is not enough to initiate a change and there is no presence of water. For the second test, the same situation is made but boiling water was filled in the tube. For this, no changes would still be observed since there is no moisture. For the last test, the same situation as the first but it is filled halfway with water. After 3 days, rust would be observed on the nails. In order for rust to happen, there should be water and oxygen. The oxygen in the early atmosphere of the Earth would react with iron present in the oceans thus producing iron ores.
        
             
        
        
        
<span>The san  Andreas fault
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Because they are the same chemical reaction but reversed. Cellular respiration takes glucose (from nutrient/food) and oxygen (from atmosphere) in order to make CO2 (think about exhaling) and H20 (water).
(I don't remember this clearly so it may be wrong, i'll look into it and come back!)
 
        
             
        
        
        
The answer is D. Light bends as it passes from one medium to another
        
                    
             
        
        
        
Answer:
Analysis of the data shows that the ratio of floating algae to sea floor algae dramatically increased at the same time that oysters were removed from the Bay. ... (It is also possible to infer from the graph that high floating algae levels led to the decline in oysters.