One of the good reason to use simulation in an experiment is to predict the outcome of an event in the real world.
Explanation:
Simulation is a programming software which helps in imaging or easy understanding of any experimental concept virtually. For example, if we enter the details regarding an element, the simulation can draw the structure of that element. Also it may predict the working of the bonds and other parameters in different conditions based on classical and quantum theoretical laws. So a researcher can compare the results obtained from simulation and also from experimental results. 
In other words, simulation will help a researcher to have an assumption about the behavior of the sample in real world conditions. 
 
        
             
        
        
        
The correct answer would be nuclear energy. The other answers would be fossil fuels because they are naturally made.
        
             
        
        
        
Answer:
Proteins is a macromolecule that helps to send signals 
 
        
                    
             
        
        
        
Explanation:
The circulatory and respiratory systems work together to circulate blood and oxygen throughout the body. Air moves in and out of the lungs through the trachea, bronchi, and bronchioles. Blood moves in and out of the lungs through the pulmonary arteries and veins that connect to the heart.
 
        
             
        
        
        
Answer:
Hawks and frogs. They both compete for the grasshoppers
Explanation: