The answer to this question would be: <span>b.electromagnetic or weak nuclear
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The electromagnetic force can be repulsive or attractive because it was influenced by the magnetic charge. The same charge (positive with positive) will be repulsive but different charge will be attractive(negative and negative). The gravitational force will always be attractive, not repulsive. 
Weak nuclear can do both like electromagnetic force.
        
             
        
        
        
Explanation:
because animals bacteria on n on that live in the rainforest nothing actually lives in a tundra 
 
        
                    
             
        
        
        
Feeling pain, hunger, thirst, sleepiness, and being aware of our thoughts and emotions are all examples of Internal stimuli.
 
        
             
        
        
        
I believe a pot of water that is being heated by a electric burner. This is because the warmer water moves to the top and the cooler water moves down to the bottom of the pot. This causes a circular motion. The next example of convection heat is a hot air ballon rising and falling in the atmosphere. A radiator is also because the hot air is drawn out the top and the cooler air is drawn to the bottom.
        
                    
             
        
        
        
The correct answer is D. RAMP because you use a ramp to reduce the amount of force needed to that work force. Hope This Helps!