根据短文内容及首字母提示，填写所缺单词，使短文意思完整。
Many people say dolphins
are very intelligent(聪颖的).
They seem to be able to think, understand, and learn things quickly. But are
they c{#blank#}1{#/blank#} like humans or more like cats or dogs?
Scientists say dolphin intelligence is s{#blank#}2{#/blank#} to human intelligence in some
ways. How?
Like humans, every dolphin has a "name". I{#blank#}3{#/blank#} is a special whistle(哨声). Scientists think dolphins,
like people," t{#blank#}4{#/blank#}"to
each other about a lot of things, such as their age, their feelings, or finding
food. And, like humans, dolphins use system (系统)of
sounds and body language to c{#blank#}5{#/blank#}.
But understanding their conversations is not easy for humans. No one
"speaks dolphin" yet, but some scientists are trying to learn.
Dolphins arc also social animals. They live in groups,
and they often come to play games from different groups and have f{#blank#}6{#/blank#}, just like people. In fact, playing
t{#blank#}7{#/blank#} is something only intelligent animals do.
Dolphins and humans b{#blank#}8{#/blank#} make plans to get something they want. In the
seas of southern Brazil, dolphins use an interesting way to get food. When fish
are n{#blank#}9{#/blank#} a boat, dolphins signal (发信号) to the fishermen to put
their nets in the water. And the men can catch a lot of fish. What is the
advantage for the dolphins? Why do they h{#blank#}10{#/blank#} the men? The dolphins can get some of the
fish.
