填空题
Some people’s ears produce wax like busy little bees. This can be a problem even though earwax ( 耳垢) appears to serve an important purpose.
Experts say it protects and cleans the ear. It (36) dirt and other matter and keeps insects out. Doctors think it might also help protect against (37) diseases. And the waxy oil keeps ears from getting too dry. So earwax is good. And there are two kinds. Most people of European or African (38) have the "wet" kind: thick and (39) . East Asians commonly have "dry" earwax.
But you can have too much of a good thing. Some people may have too much wax in their ear canal. Earwax is normally (40) ; it falls out of the ear or gets washed away. But (41) wax can harden and form a blockage that (42) with sound waves and reduces hearing. People can also cause a blockage when they try to clean out their ears--but only push the wax deeper inside. Earwax (43) is sometimes necessary. (44)
Experts at N.I.H., the National Institutes of Health, suggest some ways to treat excessive earwax yourself. (45) Another way to remove wax is known as irrigation. With the head upright, take hold of the outer part of the ear. Gently pull upward to straighten the ear canal. (46) . Then turn the head to the side to let the water out.