It is harmful because motor vehicles spit out gas and like fumes. That can lead to pollution in the air.
It is beneficial because it helps people get to places they need to get to quicker
        
             
        
        
        
Answer:
Niacin (Ans. A)
Explanation:
Nicotinamide adenine dinucleotide (NAD) is known as important cofactor which help in carrying electrons from one reaction to another reaction in the cellular respiration process.
Cells are able to restore performed compounds which are containing a pyrimidine base precursor vitamin for the synthesis of NAD: nicotinamide, nicotinic acid, and nicotinamide riboside. 
These elements are taken up from the diet whos containing vitamin B3. Nicotinamide, and nicotinamide riboside both can be absorbed from the gut. Niacin or vitamin B3 also produced within cells with the help of cellular digestion of NAD+.
 
        
             
        
        
        
Answer: Depends on where you live, in the U.S. its considered unconsitutional, but in other countries such as china, goverment offcials in bioharzard suits can take you.
Explanation:
 
        
             
        
        
        
If iodine solution reacts with starch, it will change color into black.
Since the yellow-orange iodine solution stayed the same <span>color when it was put on the apple, it can be concluded that there is no starch in the apple. On the other case, the black color of the potato suggests that there is a great amount of starch in the potato. Anyway, this does not mean that there is no starch in the apple at all. As fruits ripen, starch slowly changes to sugar. Iodine cannot react with sugar, so the black color in the apple is missing.</span>
        
             
        
        
        
Answer:
It allows information to go from one neuron to another through neurotransmitters.