Answer:
My guess is A
Explanation:
I guess it's a but dont choose it it might not be right 
 
        
             
        
        
        
Answer:
Factors that remain constant from experiment to experiment are the constants.
Explanation:
A constant in an experiment is also known as a <em>control variable</em>. It is the part of an experiment that must stay the same in order to validate the experiment. If the constant were to change, the results would be skewed and therefore false.
i.e. you want to test the rate of growth of lima bean plants in different types of lighting. You believe that a lima bean plant that grows in yellow will grow faster and stronger than a lima bean plant that grows in blue or red light.
In this experiment, the constant would be the lima bean plant. You cannot change the type of seed or else your experiment is invalidated. If you tried to use a sunflower seed in the blue lighting and a tomato seed in the red lighting, your results would be invalidated and skewed. 
 
        
             
        
        
        
Answer:
The motion of an object is determined by the sum of the forces acting on it; if the total force on the object is not zero, its motion will change. The greater the mass of the object, the greater the force needed to achieve the same change in motion. For any given object, a larger force causes a larger change in motion.
Explanation:
 
        
                    
             
        
        
        
Blood is slightly basic with a pH of about 7.35 to about 7.45.
Hope this helps! Please make me the brainliest, it’s not necessary but appreciated, I put a lot of effort and research into my answers. Have a good day, stay safe and stay healthy.
        
             
        
        
        
Natural selection is a process of adaptation by an organism to the changing environment by bringing selective changes to its genotype or genetic composition.	
Artificial selection, also called selective breeding, is the process where humans identify desirable traits in animals and plants and use these traits to develop desirable phenotypic traits by breeding.
Some examples of natural selection include the selection of long-necked giraffes and the changes in the size and shape of beaks of birds according to their feeding habits.	
Some examples of artificial selection include dog breeding to produce new breeds of dogs and cross-breeding in cash crops like wheat and rice.