Everyone needs a buddy，even jye.ai.Sharks are often described as Hollywood monsters，the lone wolves hiding in the deep，hunting for prey.But that description of sharks is increasingly out of step with what scientists are learning about the animals.Instead，they say，some species of sharks are social creatures who return day after day to a group of the same fellow sharks.
   Papastamatious's team studied gray reef sharks living in the waters off Palmyra Atoll Island.They attached small location transmitters to track the animals' movements around the reef.After tracking the sharks for four years，the researchers found that the same groups of sharks frequently returned to the same parts of the reef repeatedly.They also found that some of the groups stuck together longer than previous studies have observed.
   The sharks might be motivated to stay together，Papastamatious says，because it makes hunting for food easier. "If we hang out together and I see something，then you can come and try and take advantage of that，" he says. "And alternatively，if you see something，then I can try and take advantage of that."
   He emphasizes that the sharks don't hunt together，but says that as long as the group isn't too large—which would raise competition and conflict-socializing appears to benefit the sharks.And that may be one of the factors that led to sociality in the species.
   David Shiffman，who studies sharks' ecology and conservation at Arizona State University，says he was surprised to learn the sharks stuck together for so long. "I mean，I don't have a lot of friends I do that with，" he jokes.
   Sharks are amazing creatures，Shiffman says.In addition to knowing where to grab a bite by watching their friends，he says，some species of sharks can also learn to solve simple puzzles，just by watching other sharks solve them.Given their intelligence and social abilities，he says perhaps it's time to drop prejudices about sharks. "It turns out that they are a lot smarter than most people think，and they have come complex ability to process their environment and learn and change，" Shiffman says.

（1）Why do some sharks keep together？

D

D

A．To go back to the same reef.
B．To have fun.
C．To scare other sharks away.
D．To hunt for food with ease.
（2）In which group may sharks like socializing？

C

C

A．A large group.
B．A competitive group.
C．A small group.
D．A group filled with conflicts.
（3）What can be inferred about sharks from their behaviour？

B

B

A．They are still developing.
B．They are intelligent.
C．They are hiding themselves.
D．They are aggressive.
（4）Where is this text probably from？

A

A

A．A science magazine.
B．A travel brochure.
C．An encyclopedia.
D．A news remark.