Many science fiction stories tell about explorers arriving in a new world. The explorers then use some kind of high-tech device to test for breathable air or signs of life. But here on Earth, science fiction is becoming reality through a new sampling technology called environmental DNA, or eDNA for short. Scientists can use it to identify rare species or estimate fish populations with just a little air or water.
Environmental DNA can be used in two ways. One is to identify the creatures that live in a certain place. The other is to confirm the presence or lack of a specific creature.
Caren Goldberg is one of the first biologists to take the technology from the testing stage to actually using it. She sees eDNA as a way to get answers more efficiently and with less destruction compared to traditional survey techniques. Until recently, scientists depended on snorkeling ( 潜水), netting or using an electric current to temporarily catch fish.
This newer way to identify what lives in the environment is becoming popular around the world. Animal experts in Vietnam are using the eDNA to find the last, wild Yangtze giant softshell turtles. One researcher on the Caribbean island of Trinidad is using the sampling technology to find endangered golden treefrogs. In Madagascar, it is being used to identify amphibian(两栖动物)diseases.
Ms Goldberg has used eDNA testing to confirm the local extinction (灭绝) of a leopard frog in the American state of Idaho. She has also been asked to document the spread of the New Zealand mudsnail in the state of Washington. The creature has been found in lakes and other waterways across the state.
Scientists working with the technology say they do not expect robots to replace field biologists anytime soon. But the old-fashioned field work could soon be more targeted.
1.Compared to traditional survey techniques, eDNA is more______.
A.complex B.eco-friendly
C.dangerous D.convincing
2.By using eDNA, Caren Goldberg has______.
A.succeeded in catching many fishes
B.found the existence of golden treefrogs
C.documented the spread of softshell turtles
D.confirmed the disappearance of the leopard frog in Idaho
3.What can we infer from the last paragraph ?
A.Robots will replace scientists soon.
B.Some scientists are against using eDNA.
C.The old-fashioned field work may disappear.
D.Many biologists are unwilling to do the field work.
4.What is the best title for the text?
A.Science Fiction Becomes Reality for Species Surveys
B.Biologists Explore Space with the Help of eDNA
C.Scientists Found Methods to Test for Signs of Life
D.New Technologies Are Presented in Science Fictions
Most of the time, the ground feels solid beneath our feet. That's comforting. But it's also misleading because there's actually a lot going on underground. Masses of land (called plates) slip, slide, and bump against each other, slowly changing the shape of continents and oceans over millions and billions of years.
Scientists know that Earth formed about 4. 5 billion years ago. They also know that our planet was hot at first. As it cooled, its outermost layer, called the crust (地壳), eventually formed moving plates. Exactly when this shift happened, however, is an open question.
Now, an international group of researchers has an answer. They've found new evidence suggesting that Earth's crust started shifting at least 3. 8 billion years ago. The new estimate is 1. 3 billion years earlier than previous ones.
Not long before 3. 8 billion years ago, lots of small planets were hitting Earth, keeping its crust in a hot, melting state. After the hard crust formed, much of it sank at various times into the planet's hot insides. There, it melted before returning to the surface.
In some places, however, the crust never sank. One of the oldest such places is in Greenland, in an area called the Isua supracrustal (上地壳) belt. The rocky crust there is between 3. 7 and 3. 8 billion years old. The belt was once part of the seafloor, but now it is exposed to air.
The researchers recently took a close look at the Isua supracrustal belt. They noticed long, parallel cracks (裂缝) in the rock that have been filled in with a type of volcanic rock.
To explain this structure, the scientists propose that tension in the crust caused the seafloor to crack open long ago. Hot, liquid rock oozed from deep inside Earth to fill the cracks. Finally, the whole area cooled, forming what we see today.
That explanation, plus chemical clues inside the rock, suggests that the Isua supracrustal belt was once part of a plate under the ocean, beginning around 3. 8 billion years ago.
“It's a fantastic case of solving a jigsaw puzzle (拼图),” says one of the researchers. He notes that the puzzle was “ a very difficult one because these rocks are all very old and have been badly ruined".
1.What can we infer from the text?
A.The shapes of continents and oceans changed slowly.
B.The Earth's crust started shifting 1. 3 billion years ago.
C.The crust began to shift when the Earth was hot.
D.The hit from small planets made the Earth cool.
2.What do scientists know about the past of the Isua supracrustal belt?
A.It was once covered by the hot, liquid rock.
B.It remained under the deep sea.
C.It stayed hot and sinking.
D.It kept moving slowly.
3.The underlined phrase “oozed from” in Paragraph 7 is closest in meaning to
A.filled up gradually B.washed away quickly
C.flew out of slowly D.broke through suddenly
4.The text is mainly about .
A.why the Earth cooled
B.how the Isua supracrustal belt formed
C.whether the ground beneath our feet is still
D.when Earth's crust began shifting
One of Britain's bravest women told yesterday how she helped to catch suspected police killer David Bieber—and was thanked with flowers by the police. It was also said that she could be in line for a share of up to £ 30,000 reward money.
Vicki Brown, 30, played a very important role in ending the nationwide manhunt. Vicki, who has worked at the Royal Hotel for four years, told of her terrible experience when she had to steal into Bieber's bedroom and to watch him secretly. Then she waited alone for three hours while armed police prepared to storm the building.
She said： “I was very nervous. But when I opened the hotel door and saw 20 armed policemen lined up in the car park I was so glad they were there. ”
The alarm had been raised because Vicki became suspicious （怀疑的）of the guest who checked in at 3 pm the day before New Year's Eve with little luggage and wearing sunglasses and a hat pulled down over his face. She said： “He didn't seem to want to talk too much and make any eye contact. ” Vicki, the only employee on duty, called her bosses Margaret, 64, and husband Stan McKale, 65, who phoned the police at 11 pm.
Officers from Northumbria Police called Vicki at the hotel in Dunston, Gateshead, at about 11:30 pm to make sure that this was the wanted man. Then they kept in touch by phoning Vicki every 15 minutes.
“It was about ten past two in the morning when the phone went again and a policeman said 'Would you go and make yourself known to the armed officers outside?' My heart missed a beat. ”
Vicki quietly showed eight armed officers through passages and staircases to the top floor room and handed over the key.
“I realized that my bedroom window overlooks that part of the hotel, so I went to watch. I could not see into the man's room, but I could see the passage. The police kept shouting at the man to come out with his hands showing. Then suddenly he must have come out because they shouted for him to lie down while he was handcuffed （戴上手铐）
1.Vicki became suspicious of David Bieber because ______ .
A.the police called her
B.he looked very strange
C.he came to the hotel without luggage
D.he came to the hotel the day before New Year's Eve
2.Vicki's heart missed a beat because ______.
A.the phone kept ringing
B.she would be famous
C.the policemen had already arrived
D.she saw 20 policemen in the car park
3.The whole event probably lasted about ______ hours from the moment David Bieber came to the hotel to the arrival of some armed officers.
A.6 B.8 C.11 D.14
4.David Bieber was most probably handcuffed in ______.
A.the passage B.his room
C.Vicki's bedroom D.the top floor room
Pacific Science Center Guide
♦Visit Pacific Science Center's Store
Don't forget to stop by Pacific Science Center's Store while you are here to pick up a wonderful science activity or souvenir to remember your visit. The store is located upstairs in Building 3 right next to the Laser Dome.
♦Hungry?
Our exhibits will feed your mind, but what about your body? Our cafe offers a complete menu of lunch and snack options, in addition to seasonal specials. The cafe is located upstairs in Building 1 and is open daily until one hour before Pacific Science Center closes.
♦Rental Information
Lockers are available to store any belongings during your visit. The lockers are located in Building 1 near the Information Desk and in Building 3. Pushchairs and wheelchairs are available to rent at the Information Desk and Denny Way entrance. ID required.
♦Support Pacific Science Center
Since 1962, Pacific Science Center has been inspiring a passion for discovery and lifelong learning in science, math and technology. Today, Pacific Science Center serves more than 1. 3 million people a year and brings inquiry-based science education to classrooms and community events all over Washington State. It's an amazing accomplishment and one we cannot achieve without generous support from individuals, corporations, and other social organizations. Visit pacificsciencecenter. org to find various ways you can support Pacific Science Center.
1.Where can you buy a souvenir at Pacific Science Center?
A.In Building 1. B.In Building 3.
C.At the Laser Dome. D.At the Denny Way entrance.
2.Which of the following is NOT true?
A.If you are hungry during your stay at Pacific Science Center, you can go to the cafe in Building 1.
B.You can store your belongings in the Information Desk.
C.You can pay to use the pushchairs and wheelchairs.
D.ID card is required if you want to use the pushchairs and wheelchairs.
3.What does Pacific Science Center do for schools?
A.Train science teachers. B.Distribute science books.
C.Inspire scientific research. D.Take science to the classroom.
假定你是李华，你市图书馆将举办中国茶文化展览。你校外教Smith先生对此很感兴趣，请用英语给他写一封邮件，邀请他参加该活动。内容包括：
1. 展览时间及地点；
2. 展览内容：中国茶的历史、文化；茶叶、茶具等；
3. 观看茶艺表演、品茶。
注意：1. 词数100左右；
2. 可以适当增加细节，以使行文连贯。
参考词汇：茶具tea set；茶艺the art of tea-making
Dear Mr. Smith,
___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Yours,
Li Hua
概要写作：阅读下文，根据其内容写一篇50-60词胡内容概要。
For decades, doctors have warned patients that too much salt can be bad for the heart. Heart attack has long beenconsidered a grown-up problem, but new research suggests that salt is starting to affect children. Eating too much salty food when you’re young can lead to health problems later.
Salt is made up of two elements: sodium andchlorine. Dietary guidelines recommend that adults and kids aged 9-13 shouldn’t consume more than about a teaspoon of sodium daily. The average American eats twice this amount.This worries doctors because too much sodium results in the body producing more blood. To pump the extra blood, the heart has to work harder. This causes a rise in blood pressure---a measurement of how stressed the heart is. High blood pressure often leads to heart disease.
A kid with high blood pressure is more likely to become a grown-up with high blood pressure. Reducing salt might also help stop childhood obesity. British researchers recently found that kids who eat less salt also drink fewer sugary soft drinks. Drinking fewer fizzy drinks makes kids less likely to gain weight, become obese and develop high bloodpressure.
Salt can affect more than just your heart and weight. A recent study found that a growing number of kids in theUSaresuffering from kidney stones. This painful condition usually affects people aged over 40. Now, kids as young as five are getting it.
Cutting down on salt can be hard, but you can retrain yourself to prefer less salty food. The best way to reduce the amount of sodium you eat is to make changes gradually. Start by adding half as much salt to your dinner as you normally do. Switch to fresh foods instead of canned and bottled versions. And go easy on the condiments. You might also want to start reading nutrition labels. You may be surprised to learn that there are1,150 mg of sodium in a double cheeseburger, and over 2,000 mg in many frozen meals.
