3 . Relatives of starfish, brittle stars (海蛇尾) spend most of their time hiding under rocks in the ocean or digging in the sand. These shy marine creatures have no brain to speak of—just nerve cords running down each of their five wiggly arms, which join to form a nerve ring near their mouth.

“There’s no processing center. Each of the nerve cords can act independently. Instead of a boss, it’s like a committee. That seems to be enough to learn by association,” said lead author Julia Notar. This type of leaning involves associating different stimuli via a process called classical conditioning (条件反射).

Classical conditioning has been demonstrated in a handful of previous studies in starfish. But brittle stars and similarly brainless starfish have not been tested.

To find out if brittle stars have the ability of learning, the researchers put 16 black brittle stars in individual water tanks and used a video camera to record their behavior. Half the brittle stars were trained by dimming the lights for 30 minutes whenever the animals were fed. Every time the lights went out, the researchers would put a bit of shrimp in the tanks, placed just out of reach. The other half got just as much shrimp and also experienced a 30-minute dark period, but never at the same time—the animals were fed under lit conditions.

Whether it was light or dark, the animals spent most of their time hiding behind the filters in their tanks, only coming out at mealtime. But only the trained brittle stars learned to associate darkness with food. They didn’t need to smell or taste the shrimp to react.

Notar said the results are exciting because classical conditioning hasn’t really been shown definitively in this group of animals before. “Knowing that brittle stars can learn means they’re not just robotic scavengers (清道夫) cleaning up the ocean floor,” Notar said. “They’re potentially able to expect and avoid predators (捕食者) or expect food because they’re learning about their environment.”

5 . 为了丰富校园生活，你校将组织迎新年音乐会，请你写一则通知，刊登在学校英文网站上。内容包括：

1. 举办时间和地点；

2. 活动的内容；

3. 活动的意义。

注意：词数80左右。

Notice

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8 . Pat Patterson, a pilot for 25 years, had never met anyone like the handsome young man in the wheelchair who faced him at the Medford, Oregon, airport on July 28, 1976. Mike Henderson, a quadriplegic (四肢瘫痪者), wanted flying lessons.

As a 22­-year-­old Coast Guardsman eight years before, Henderson had fallen off a dock and landed on a floating log, breaking two of his bones. Doctors said that he would probably never walk again, let alone fly. “Here was this doctor telling me how it was going to be,” he says, “but no one was going to limit my freedom to try.”

Henderson parked his wheelchair next to the airplane and began to climb up onto the wing. He injured his elbow on the way, and after a great struggle, finally managed to pull himself into the airplane’s pilot’s seat. In the flight office, Pat Patterson watched in disbelief. “He crawled his way up that wing!” he says. “It took him 45 minutes. When I went out, he was sitting in the pilot’s seat, bleeding from his injured elbow all over the place. When I saw him go through that much pain, I knew nothing could stop him.”

Now everything was up to the instructor and the student, and together they set about solving each problem as it arose. A small piece of carpet gave Henderson traction (摩擦力) to climb the slippery wing. A headset freed his hands from the radio microphone, and the two men developed a moving bar that enabled Henderson to operate the airplane more easily.

Three weeks and eight flying hours after the first lesson, Henderson and Patterson happily phoned Dr. Stoddard — Henderson’s physician. At the airport, as the physician looked on, Henderson quickly wheeled himself around the airplane, doing a thorough, professional ground check. With Patterson and Dr. Stoddard on board, he went through his preflight instrument check. Minutes later, engine starting, the plane rolled down the runway and took off into the gray sky.