Southern long-finned pilot whales are marine mammals with a lot to say—and they may use vocalizations (发声) to outsmart a deadly enemy.

Cetaceans (鲸类动物) such as whales and dolphins communicate through sound to find food and mates, to navigate and to interact socially. Their vocalizations _________ between species and within communities. The animals can mimic (模仿) artificial noise such as sonar, but nobody had previously recorded them _________ other cetaceans’ sounds. A new study, however, found overlap in the cetacean sound book.

Researchers listened to 2,028 vocalizations of long-finned pilot whales off the coast of Australia, the first time sounds from the species in this region have been _________ described. They were surprised to hear 19 instances of vocalizations that resembled those of orcas—the whales’ oceanic _________. “We found some calls that are, to the human ear, _________ to the killer whale calls in the same area,” says Christine Erbe, an expert in Marine Science and Technology.

Pilot whales and orcas, the two largest species of cetaceans, are often seen in the same _________ and are similar sizes, and both live in social groups. Orcas compete for food with long-finned pilot whales and are _________ their predators (猎食者) .

_________ from orca stomachs shows they do occasionally eat pilot whales. But pilot whales can mob and chase orcas away, the only cetaceans seen _________ themselves from their predator in this way.

Mimicry could serve as an __________ defense: “One theory is that if they use similar sounds, they may not be recognized as prey,” Erbe says. Pilot whales hunting or eating orcas’ food remainders might go __________ if they use orca-like calls. “This is all underwater, where light travels really poorly,” she adds. “So these animals __________ sound for detecting their prey and predators and for navigating.” Long-finned pilot whales have shown an ability to __________ between orca calls with different meanings.

Additional work would __________ whether mimicry is actually occurring. Researchers could pair their listening data with direct observations of the animals’ interactions in the wild or perhaps even play orca sounds and watch the whales’ __________.

When we talk about a bad man, we like to call him a “wolf”. But is it really true that the wolf stands for devil (恶魔) and ugliness? Have you read the book The Wolf Totem (图腾) by a famous writer Jiang Rong, which tells the story of the relationship between wolves and human beings? Have you ever _______the wolves’ world? If you had, you would _______the wolves.

In the book, wolves are heroes on the large grassland. They know more about _______than humans. They can attack lambs without disturbing their mothers. They also know how to_______full use of the shape of land to _______sheep. I believe that if wolves were humans, they would be _______experts good at fighting. The wolf is a kind of special creature that can deeply understand ________. Each wolf serves its group with its heart and soul. A _______wolf has little power, but a pack (群) of wolves _______nothing. All the wolves obey the rules. ________they are defeated, they run away together. It is their teamwork ________makes wolves powerful.

The wolves also have great self-respect and won’t ________to anyone. The writer, who wrote the book The Wolf Totem, ________stole a one-month-old baby wolf and raised it very carefully. To his ________, he found the little wolf still wanted to go back with the ________wolves. He bit through the iron chain that limited him. The wolf was ________and he never gave in, fighting to his _________ . The little wolf died as a glorious fighter.

When my son, Justin, was four, he found a caterpillar (毛虫) and put it in a jar. Each day he fed it with fresh grass and leaves. In a few weeks we discovered it _________in a cocoon (茧).

Justin was excited. He knew a moth (蛾) or butterfly was about to be _________, but he didn’t know what kind. He was_________to know what gift nature was about to give him.

“Dad!” shouted the boy while running to me one day. “Something’s _________. Come see!”

He led me to his room. The cocoon had become half transparent and we could _________ the wings of the unborn. Soon, a moth broke free from the cocoon, and laid eggs completing the life _________of the little caterpillar.

The next day, I convinced Justin it was time to set the moth free. He took it _________ , opened the jar, and the little moth flew out. It _________the yard twice, came back, and landed on Justin’s arm. He picked it up, tossed it in the air, and the moth repeated its _________ pattern. He tried over and over, but each time it would __________ to his arm.

Justin__________. He put his little pet back to the jar. The next day he attempted to set it free again, and after a few repetitions of the same behavior, the moth__________flew off into the grass.

Like a __________, I believe the moth was afraid to leave what it was comfortable with. It wanted to stay with something__________, scared to move on and experience something unknown.

I was once that little moth. My cocoon was my mother’s __________ , in which I was comfortable. Like the moth, I didn’t want to fly too far away from it. I was__________ when my first job required me to move to a new city. What would I find there? I liked__________I was.

Humans are creatures of __________. We resist change. However, if I hadn’t moved, I would not have experienced many__________and wonderful things or met many of my friends. So each move gave me the __________to learn and experience, but best of all, I met friends.