Question at bottom you

eyelashes: slow growth view passage image when was the last time you got your hair cut? if your hair is very short, it might have been only a few weeks ago. if your hair is very long, it was probably many months (or even years! ) ago. now think back to the last time you got your eyelashes cut. how long ago was that? chances are, your answer to that question is “never.” but if that is the case, then why are your eyelashes so short? would it ever be possible to have eyelashes that are as long as the hair that comes out of your head? to answer this question, we must first understand a few basic facts about your hair. every hair on your body grows out of something called a follicle. the follicle is the part of the hair that grows underneath the skin. it is almost like the root of the hair. the outer part of the hair—the part that grows on the outside of the body—is called the shaft. each piece of hair, whether it is hair from your head, your arm, your nose, or your eyelids, grows in its own follicle. your hair is not always growing. instead, it goes through phases (periods or stages) of growth and phases of rest. in other words, your hair is either growing or it is resting. when the follicle has finished growing, it enters the resting phase. during the resting phase, the hair shaft breaks and the old hair falls out. the follicle then enters the growth phase once again. this repeats in a cycle, as new hair constantly replaces the old hair. the length of a hair depends on the length of its growth phase. different types of hair on your body have different growth phases. the longer the growth phase is, the longer the hair gets. the hair on your head has the longest growth phase. the exact length of the scalp hair growth phase differs from person to person. some people's hair can grow for six or seven years; for others, the growth phase only lasts two years. compared to your scalp hair, your eyelashes have a very brief growth phase. the growth phase of an eyelash is only 30 days long. this means that the hair on your head can grow much, much longer than your eyelashes. the hair on your head can grow up to 40 inches; in contrast, the average eyelash length is only half an inch long. some people use mascara or other kinds of make-up to make their eyelashes look longer, but they are not actually increasing the length of their lashes by doing this. once your eyelashes reach their maximum length, they enter the resting phase. your eyelashes spend far more time in the resting phase than your scalp hair does. when a hair from your head falls out, it is quickly replaced with a new hair. when an old eyelash falls out, it takes a much longer time for a new one to replace it. in fact, if an eyelash gets pulled out, it can take up to two months for a new one to grow in its place. this is why it seems like your eyelashes do not grow. they are growing--just very slowly. even though it takes a long time for your eyelashes to grow, it is important that they do! your eyelashes keep dirt and dust out of your eyes. they also act as a warning system. when your eyelashes sense that something is getting too close to your eyes, they trigger the blinking reflex. this causes your eyelids to close, protecting your eyes from danger. our eyelashes are the perfect length for keeping our eyes safe and clean. it is probably for the best that they never get longer than half an inch. after all, if they got too long, it would be awfully difficult to see where we were going!

based on the way it is used in paragraph 5, which of the following activities is the most brief?
a. a twelve-hour flight across the ocean
b. a five-minute walk around the block
c. a two-hour nap on the couch