I think true if its not sorry
 
        
                    
             
        
        
        
Mass is measured by using a balance comparing a known amount of matter to an unknown amount of matter. Weight is measured on a scale.
 
        
             
        
        
        
Answer:
Answer is D - cAMP.
Explanation:
cAMP is a small molecule that functions as an intracellular signaling molecule - a second messenger. The first messenger would be the thing that activated the GPCR (e.g. a hormone). The GPCR is a signal transducer (converts extracellular signal to intracellular signal). Once activated, the GPCR activates  adenylate cyclase which can be called a signal effector - it is an enzyme that produces cAMP.
 
        
             
        
        
        
Eye strain - hope this helped
        
             
        
        
        
Answer:
Gravitational force 
Explanation:
Gravitational force is the force that attracts an object down to the earth. It’s also the reason why we don’t float on this planet. This force is also why anything that isn’t thrown up must come down.
In space and other planets with little or no gravitational force ,organisms float over there which makes its inhabitation by organisms very difficult.