When humans make friends, we often choose companions who share similar characteristics to us or enjoy participating in the same activities that we enjoy. Interestingly, it turns out that dolphins (海豚) may not be so different, according to a study which found that the animals form strong social ties with those who have similar interests. In some ways, this may not be surprising, if we know dolphins live in groups characterized by complex social activities. However, the latest findings are yet another powerful example of the intelligence that these creatures possess.

For the study, an international team of scientists studied a unique group of bottlenose dolphins, who live in the World Heritage area of Shark Bay, Western Australia. They are particularly interesting because the females are known to use sea sponges (海绵动物) as foraging (觅食) tools, a behavior that hasn’t been perceived anywhere else. The behavior known as “sponging,” helps the dolphins to find food in deeper waters and is socially-learned, being passed down from mother to baby.

Previous studies have shown that females in this group who use sea sponges to find food often like to hang out with other females who do the same. However, studies of this behavior in males are lacking, leaving a gap (空白) in our knowledge. To try and address this gap, the researchers collected data on 124 male dolphins in Shark Bay over a 9-year period between 2007 and 2015. Among these dolphins, some had the sponging behavior, while others did not. After analyzing their data, the team came to the conclusion that those males who used sponges for foraging associated significantly more often with other “spongers,” no matter how related they were to their companions. Interestingly, male spongers spent significantly more time foraging and less time resting than non-spongers.

According to the lead author of the study, Manuela Bizzozzero, the findings cast new light on the social ties between male dolphins at Shark Bay.

【小题1】What can we learn form the first paragraph?

A．Dolphins are humans’ best friends.

B．Dolphins make friends like humans.

C．Dolphins can understand humans’ emotions.

D．Dolphins confuse humans with their lifestyles.

【小题2】What does the underlined word “perceived” in Paragraph 2 probably mean?

A．Influenced.	B．Prevented.
C．Observed.	D．Accepted.

【小题3】Why does the author mention previous studies in Paragraph 3?

A．To explain the intention of the latest studies.

B．To present their achievements in dolphin research.

C．To stress that dolphins have the socially-learned behavior.

D．To show how female dolphins use sea sponges to find food.

【小题4】What’s the result of the studies on male bottlenose dolphins?

A．Few of them make use of sponges to find food.

B．A large quantity of them mainly feed on sponges.

C．Male spongers rest more often than non-spongers.

D．Male spongers enjoy staying with other spongers.