Jutroduction

馬薩諸塞州伍斯特理工學(xué)院一支以學(xué)生為主的研究團隊研發(fā)出了一種水下機器人，可追捕獅子魚。獅子魚是位于食物生態(tài)鏈上端的食肉動物，專門捕食珊瑚礁健康生長所需的海洋生物，繼而對珊瑚礁造成了嚴(yán)重威脅。

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(捕食性動物)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 tohunt downlionfish.The team recently demon-strated the device and is continuing to test and make changes to it.

The robot is designed to recognize the lionfish,chase afterit 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.

Reading Check

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.

Language Study

I.Important vocabulary in the text

1.kill off大量消滅；大量殺死

2.hunt down搜尋

3.plot out a course繪制路線圖

4.chase after追逐；追捕

5.perfect v.使完美

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

1.我們繪制出前往那些小島的路線圖。

We___________for those small islands.

2.他熱衷于提高自己的高爾夫球技。

He is keen to___________his golfing technique.

3.她在追趕一個搶走她包的男子。

She was___________a man who had snatched her bag.

4.必須把恐怖分子緝拿歸案、繩之以法。

The terrorists must___________and brought to justice.

5.大肆殺戮灰熊等食肉動物會使生態(tài)系統(tǒng)失去平衡。

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