题型:阅读理解 题类:常考题 难易度:普通
江苏省启东中学2019-2020学年高一上学期英语第一次质量检测试卷
A person can use all five senses while spending time with dolphins. We can see them play in the waves, hear them call, and feel their skin. Dolphins can sense you, too, but not in all the same ways. They have good eyesight, for example, but no sense of smell. Sensory biologists try to understand connections between animal behaviors and the senses. One team of these scientists recently made an unexpected discovery about certain dolphins.
The researchers found that Guiana dolphins can detect electric fields, an ability that may help them find fish to eat. The secret to this newly found sense, say the scientists, is hidden in the dolphins' snouts (口鼻部).
"We were really surprised to find this in the dolphin. Nobody had expected it," said Wolf Hanke, who led the new dolphin study.
Hanke and his team suspected the dolphin's electro-sense might have something to do with small dimples (酒窝) on the animal's snout. "We thought they must have some functions," Hank said. To find out for certain, his team studied two Guiana dolphins.
The scientists first studied the dimples of a 29-year-old dolphin that had died of natural causes. Under a microscope, the dimples looked familiar: they were similar to the sensors used by other animals to detect electric fields.
Next, Hanke and his team tested a live dolphin, a 28-year-old named Paco, to see if he could recognize an electric field. They taught Paco to swim close to a device that could create a weak electric field in the water. Then the team taught Paco to swim away from the device if he detected any changes. When the scientists created an electric field, Paco swam away—showing that he knew something had changed. When there was no electric field, Paco stayed there. When Paco's snout was covered in plastic, he didn't react to the electric field.
Paco's behavior told the scientists that the dolphin used his snout to detect the tiny electric field. "This is a major breakthrough," Peter Madsen, a sensory biologist, said.
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