五.閱讀測驗(每題2分,共20分)         One of the most special features of dolphins is the ways they communicate with other dolphins. The most common way is the use of whistles. Over half of the sounds which a dolphin uses is “the signature whistles.” As the name shows, a signature whistle is how dolphins make themselves different from others. It is similar to human’s fingerprint. They have learned to have their own signature whistles since they were born. Interestingly, the signature whistles of most female dolphins are different from their mothers’, but almost half of the male dolphins’s signature whistles are similar to their mothers’.         They also use many other kinds of whistles to catch dolphins’ attention(注意力). This is like we call people’s names to get their attention. Also, they use whistles to make others notice the danger in the sea or give directions. Many scientists are interested in dolphin whistles. They even think that maybe humans are able to communicate with dolphins someday in the future.

【題組】( )46 According to the reading, whistles is a kind of ____________.
(A) pool
(B)shape
(C)glue
(D) sound