史婕

馬萨诸塞州伍斯特理工学院一支以学生为主的研究团队研发出了一种水下机器人，可追捕狮子鱼。狮子鱼是位于食物生态链上端的食肉动物，专门捕食珊瑚礁健康生长所需的海洋生物，继而对珊瑚礁造成了严重威胁。

Lionfish are known for their beauty and unusual look， a common choice for people showing off the colorful creatures in fish tanks. But lionfish are also poisonous， with extremely long and separated spines（刺毛） to carry and shoot poison.

The native environment for lionfish includes the South Pacific and the Indian Oceans. However， sea experts say lionfish were at some time released into the Atlantic Ocean， likely by people who had kept them in tanks.

Lionfish are currently considered a great threat to coral reefs（珊瑚礁） and related sea life in coastal waters of the southeastern United States and Caribbean. Scientists say the fish is a top predator （捕食性动物） that competes for food and space with native fish in the area. Lionfish kill off and eat many other kinds of fish that are important in helping coral reefs grow and stay healthy.

The US National Oceanic and Atmospheric Administration （NOAA） says lionfish reproduce very quickly and are continuing to expand. NOAA scientists predict further reef damage as lionfish keep attacking fish populations already threatened by the effects of climate change， pollution and overfishing.

Now there is a new solution for fighting back. A student-led team at Worcester Polytechnic Institute in Massachusetts developed a robot to hunt down lionfish. The team recently demonstrated the device and is continuing to test and make changes to it.

The robot is designed to recognize the lionfish， chase after it and shoot the animal with a spear（矛）. The spear then separates from the robot and floats the fish to the surface for collection. The robot is equipped to operate underwater without human control.

Craig Putnam， a computer science professor at Worcester Polytechnic Institute and a director of the school's Robotics Engineering Program， says the team's goal is to be able to drop the robot over the side of a boat and have it go down to the reef， plot out a course， and begin its search. Putnam notes the robot will be required to follow a complex path to avoid the reef， other sea creatures and people to reach and catch its target. But his team is hopeful that the fish-like vehicle can “be a part of the environmental solution” to limit further damage. His team trained the robot system by showing it thousands of images of lionfish in different colors， from many directions and under different lighting conditions. “The robot can correctly identify lionfish about 95 percent of the time，” he added.

The team said one of the hardest parts of the project was designing a container for the robot's electronics system to protect it from the harmful effects of salt water. In the coming months， the team will be working to perfect the robot's satellite guidance system.

The researchers hope that in addition to helping reduce reef damage， the system can also provide economic help. They say that since lionfish are a popular food， fisherman could use the robots to safely catch the fish and sell it to local restaurants.

1.Why should lionfish be killed off in the oceans？

A.They are a popular sea food in restaurants.

B.They are poisonous and harmful to humans.

C.They are reproducing and expanding too quickly.

D.They are top killers of fish populations good for coral reefs.

2.What's the second step an underwater robot would take in hunting lionfish？

A.It aims and shoots a spear at the lionfish.

B.It floats the lionfish to the water surface.

C.It searches around and recognizes a lionfish.

D.It follows along until tracking down the target.

I.Important vocabulary in the text

1.kill off 大量消滅;大量杀死

2.hunt down 搜寻

3.plot out a course 绘制路线图

4.chase after 追逐;追捕

5.perfect v. 使完美

Ⅱ.Complete the following sentences using the vocabulary given above.

1.我们绘制出前往那些小岛的路线图。

We  _______  for those small islands.

2.他热衷于提高自己的高尔夫球技。

He is keen to  _______ his golfing technique.

3.她在追赶一个抢走她包的男子。

She was   _______  a man who had snatched her bag.

4.必须把恐怖分子缉拿归案、绳之以法。

The terrorists must   _______ and brought to justice.

5.大肆杀戮灰熊等食肉动物会使生态系统失去平衡。

_______ predators such as grizzly bears could throw the ecosystem out of balance.