问题详情：
Dolphins live in a dark underwater world. It’s often impossible to see each other or anything else around them, so sound plays an important role in their survival. To communicate with each other, dolphins produce all kinds of sounds.
Only other dolphins understand what the sounds mean. Scientists haven’t uncovered their secret communication, except for one kind of whistle. It might last less than a second, but this whistle is a big deal. Why? Because these whistles are actually names of dolphins - and every dolphin has one. Scientists call these sounds a “signature whistle.” When other dolphins hear the whistle, they know which dolphin is whistling.
Dolphins often hunt by themselves but still need to stay connected to the group. Since they can’t always see each other, dolphins use their signature whistles to check in with other dolphins hundreds of yards away. “In coastal areas, dolphins exchange whistles even when they’re a third of a mile apart,” says Greg Campbell, who studies animals. That means dolphins shout out to group members that might be nearly five football fields away. What’s amazing is who names the baby dolphin. Not the mother. Not an auntie dolphin or another group member. Scientists believe the baby dolphin itself comes up with the signature whistle.
Like human babies, a baby dolphin plays with sounds throughout its first year. While testing its sound skills, a baby dolphin is doing something amazing. It’s creating or figuring out its signature whistle. How or why it chooses its signature whistle is not clear. Studies show that most of the time the signature whistle is nothing like its mother’s or group members’ whistles.
When the baby dolphin is about a year old, its signature whistle is set. The baby dolphin repeats it often so the other dolphins learn to recognize it.
Deciphering (破译) dolphin names is just the beginning of figuring out what dolphins communicate about. Do they chat about sharks? Discuss the tides? Maybe they even have a name for people. Someday scientists are to decipher the rest of dolphins’ communication.
12．Sound is important for dolphins because of ______.
r poor sense of direction r living environment
r strong enemies r big groups
13．The dolphin’s signature whistle ______.
last a long time travel long distances
discuss the tides be recognized by other animals
14．The author writes the text mainly to ______.
urage readers to study dolphins
all the information of dolphins
how lovely and clever dolphins are
oduce a special sound made by dolphins
15．A baby dolphin gets its name ______.
after it was born rding to its size
by itself the help of its group
【回答】
BBDC
知识点：科普环保类阅读
题型：阅读理解
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