Choices 1, 2, and 3 all emit carbon dioxide, not enough to destroy the planet, but they still can cause it over a large amount of time, due to Carbon Dioxide being a greenhouse gas. Therefore, the answer is 4. Bicycles do NOT emit any carbon dioxide at all.
        
             
        
        
        
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.
        
             
        
        
        
Because by damaging capsids, there is no place for the bad DNA to be stored. So the drug destroys the DNA so no more of the virus can be stored in the body.