根据短文内容及首字母提示，补全空格内单词，使短文完整、通顺。
For
a long time, people thought that the floor of the ocean was a very quiet place.
Some thought that it was almost without any s{#blank#}1{#/blank#} at all. Scientists were
surprised when they put a microphone (麦克风)
under water and heard all kinds of noises. They heard grunts, growls, snarls
and whistles. The b{#blank#}2{#/blank#} of
the sea sounded like a zoo! The scientists were puzzled (迷惑的) when they found out
these noises were c{#blank#}3{#/blank#} from fish. Some fish make
noise by grinding their teeth. Others scrape their bones together. Still others
make noise with the sac of air in their bodies. W{#blank#}4{#/blank#} fish make these sounds is somewhat a mystery
(谜). Some scientists think
that the fish use these noises to s{#blank#}5{#/blank#} to one another. Most people
believe the sounds have no meaning. Scientists have found out that the dolphin
k{#blank#}6{#/blank#} the meaning of some
sounds. Tests show that it is one of the smartest a{#blank#}7{#/blank#} in the sea. People say
that they have been able to teach the dolphin many human words. At Marineland
of the Pacific, it is said that dolphins have even been taught to sing. They
rise to the s{#blank#}8{#/blank#} of the water and sing for
visitors. At least it sounds somewhat like singing!
Who knows? We may be able to
talk with the dolphin and learn many secrets of the sea sometime soon. Just
think what the dolphin could tell us. We could learn the location of treasure
ships u{#blank#}9{#/blank#} the sea. We could learn
where to find great schools of fish. We might e{#blank#}10{#/blank#} learn the location of
submarines (潜艇). It
could be an exciting moment when we first begin to find
out what those voices from the ocean floor are saying.
