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 (47) an important purpose. Experts say it (48) and cleans the ear. It (49) dirt and other matter and keeps insects out. Doctors think it might also help protect against (50) . And the waxy oil keeps ears from getting too dry.
So earwax is good. It even has a medical name: cerumen (耵聍). There are two kinds. Most people of European or African ancestry have the "wet" kind. thick and (51) . East Asians commonly have "dry" earwax.
But you can have too much of a good thing. The glands (耳道) in the ear canal that produce the wax make too much in some people. Earwax is normally (52) ; it falls out of the ear or gets washed away. But extra wax can harden and form a (53) that interferes with sound waves and reduces (54) .
People can also cause a blockage when they try to (55) out their ears, but only push the wax deeper inside. Earwax removal is sometimes necessary but you have to use a (56) method or you could do a lot of damage.
A. sticky
B. hard
C. expelled
D. protects
E. listening
F. clean
G. hearing
H) safe
I) blockage
J) made
K) infections
L) partly
M) serve
N) traps
O) slight