Answer:
Earth's water is always in movement, and the natural water cycle, also known as the hydrologic cycle, describes the continuous movement of water on, above, and below the surface of the Earth. Water is always changing states between liquid, vapor, and ice, with these processes happening in the blink of an eye and over millions of years.
Hope this helped!! :))
Explanation:
 
        
                    
             
        
        
        
The force of attraction between two objects can be illustrated using Newton's Law of Universal Gravitation.
The relation between the different parameters is shown in the attached image.
Now, from the relation, we can deduce that the force between the two objects is directly proportional to the masses of the two objects.
This means that, if the mass of one object is doubled, then the force between the two objects will also be doubled.
 
        
        
        
Solar energy is that energy remaining from the sun that we store in solar panels. This energy is produced because of its nucleus.
        
                    
             
        
        
        
Mechanical advantage is the ratio of output force to input force of a machine.
hope this helps and have a great day :)
        
                    
             
        
        
        
Answer:
D.
a control group
Explanation:
In a scientific experiment such as the one above, there is an experimental group and a control group. The experimental group is the group that receives the treatment while the control group does not receive any treatment. The control group helps the researcher to observe if the treatment had any significant effect. 
In this case, it will help Alan and Monica to determine if fertilizer X actually had an effect on the plant. Therefore, the pot with o grams of fertilizer in it is the control group.