Answer:
D
Step-by-step equation:
-10 + 30 = 20
It's like walking ten meters to the left, then walking thirty meters to the right. The result is walking 20 meters to the right. It's the same with force.
 
        
             
        
        
        
Answer:
diffusion in the air molecules 
osmosis in water molecules 
 
        
             
        
        
        
Answer:
The correct answer is methane . Nature constitutes most of the substances made up of organic compounds. These compounds have carbon atoms attached with hydrogen atoms with a chemical bond (very few compounds may not have this bond).
 
        
                    
             
        
        
        
I thought it was (d) but I might be wrong