A new study suggests climate conditions in the Sahara Desert, one of hottest, driest and most deserted areas in the world, have changed from wet to dry a about every 20,000 years.
But previous evidence has suggested the Sahara did not always experience such extreme heat and dry conditions. At times, the Sahara Ranged to a very wet climate. This permitted plants and animals to develop and grow and led to the creation of human settlements. Now, they have discovered more evidence, which, the lead researcher David Mc Gee says, supports the idea that the Sahara's climate kept changing between wet and dry about every 20,000,years.
McGee reported these climate changes were mainly driven by changes in the Earth's(地轴)as the planet travels round the sun .This process affects the amount of sunlight between seasons. Every 20,000 years the Earth receives more strong summer sunlight. When the Earth's axis changes again, the amount of sunlight is reduced. This season change happened continuously every 20,000 years. The other part of the season produced rainy conditions, resulting in a wetter, greener, plant-rich environment. When the rainy activity weakens, the climate becomes hot and dry, like the Sahara remains today.
The scientists based their research on dust collected from ocean sediment(沉积物)in the Atlantic Ocean bottom off the coast of West Africa. The dust contained layers (层)of ancient sediment built up over millions of years. Each layer could contain traces of Saharan dust as well as the remains of life forms. This information was used to assess over what time period the dust had built up. This led to the overall finding that the Saharan changes from wet to dry climates happened every 20,000 years.
David McGee said that today we only see the Sahara Desert as an extremely deserted and “inhospitable” place. The new study suggests that the area's climate has changes between grasslands and a much wetter environment, and back to dry climates, even over the last quarter million years. McGee says he thinks the latest research can be valuable in studying the Sahara's history as it relates to human settlement.
1.What does the new study find about the Sahara Desert?
A. It is one of the hottest, driest and most deserted areas in Africa.
B. It always experiences extreme conditions because of its position.
C. Its climate changes between wet and dry about every 20,000 years.
D. Its environmental conditions stop plants and animals from surviving.
2.What is the direct reason for Sahara's climate changes?
A. Rainy activity. B. Solar radiation.
C. Human activity. D. Global environment.
3.How did the researchers acquire the evidence?
A. By analyzing ocean life.
B. By studying Sahara’s history.
C. By collecting dust on the coast.
D. By examining mean sediment.
4.What does the underlined word “inhospitable” probably mean?
A. Unsuitable to live. B. Insignificant lo study.
C. Unable to explore. D. Impossible to change.
John George, 60, remembers that he lived a wonderful life in the Detroit neighborhood where he grew up. “We knew all our neighbors.” George told Detroit's Metro Times. “On Christmas Eve, we'd all go to midnight Mass, and there'd be 300 people in our house at one o’clock to about five in the morning. The folks were just really good, hardworking people. ”
By the'80s, however, the old neighborhood changed. Due in part to economic downturns and drug abuse, well -kept homes had been abandoned and kindly neighbors had fled to the suburbs(郊区). But not George. “Living in any city, it’s like being in a relationship,” he told Reader’s Digest. “Some days are better than others. But it was my home. And when I saw it becoming worse, I had two choices: I could leave, or I could stay and fight. I chose the latter.”
When the abandoned home behind his turned into a worn-out place, the father of two grabbed some boards and nails and began boarding up the house. After two neighbors stopped to ask what he was doing, they decided to help, with great results.
That's how it all got started. In the 30 years since that first home rescue, an army of approximately 182,000 volunteers, along with private donors, has helped George pull down around 300 abandoned homes, mainly in die poorer Northwest area of Detroit. They've also secured 400 - some homes by boarding them up. They've painted and repaired nearly 900 homes and built over 100 from scratch. According to Forbes, more than 1,000 Detroiters have been housed as a result of their work.
And there's Halloween. In Detroit, October 30 was known as Devil's Night, a period when all hell break loose in the form of crime and vandalism (破坏公物). In response, George created a citizens' patrol(巡逻)that would take to the streets, keeping an eye on illegal behavior. He named it Angels' Night What began with 12 neighbors on patrol in 1990 has grown to more than 60,000 citywide.
George's inspired ideas have not gone unnoticed by the city he loves. Others are buying into it. There's a trend of younger homeowners coming in.
1.What was George’s home city Detroit like before the ’80s?
A. Neighbors were nice and got along very well.
B. People in the suburbs led a wonderful life.
C. Economy declined because of drug abuse.
D. Many homes were abandoned and people lied.
2.What did George decide to do after his neighborhood changed?
A. Move to the suburbs. B. Leave his hometown.
C. Join his neighbors to help. D. Stay and fight to save his city.
3.What happened as a result of George and other volunteers' hard work?
A. More people moved into Detroit.
B. Almost all Detroiters were housed.
C. Over 100 homes were newly built.
D. There was no illegal behavior any more.
4.What does the story mainly intend to toll us?
A. Great minds think alike.
B. Two heads are better than one.
C. A friend in need is a friend indeed.
D. Little people can make a big difference.
In the U. S. state of Washington, a road called Interstate(州际公路；州际的)90 cuts through a wild mountainous area to reach the city of Seattle. For the area's many kinds of animals, busy high- way greatly limits their movements. Animals need to move to find food, to find mates, to find new places to live as their populations expand or just when conditions change, like a fire breaks out. Crossing I-90 – as the road is called – is a risky but sometimes necessary act. But soon, animals will have a safer choice. They will be able to go above it.
To help the animals, the state is finishing work on its largest - ever wildlife bridge. The 11-meter-tall, 20 - meter - wide bridge begins in the forest. It forms two arches above the highway, one for each direction of traffic. Workers are adding fencing anti plants to help guide the animals across the bridge，Two-meter-thick walls will help block noise from vehicles below. Scientists chose the area because it is within a natural migration(迁徙)path for some animals.
The I -90 bridge is part of a growing number of wildlife crossings across the United States. Some are fences, some are overland bridges，and some are underpasses. They all aim to keep drivers and animals away from each other.
A U. S. Transportation Department study found crashes between animals and humans rose year by year. The accidents made up about 5 percent of all crashes nationally, and cost the economy (经济)about ＄ 8 billion. Such costs come from car repaid, emergency room visits and removal of the dead animals on roads. Collisions between animals and drivers are rarely deadly to people. But they are often deadly to wildlife. The study also found that 21 endangered or threatened species in the U.S. are affected by vehicle hits. Bridges, underpasses and fencing reduce I he area's animal - driver collisions by 80 percent.
Most of the wildlife bridges are in western states. Many other areas also need such paths. But finding money for more crossings is“the- number - one problem”. Patty Garvey — Darda of the U. S. Forest Service has worked on the I - 90 crossing from the start of the project. She says the $ 6 - million bridge will one day pay for itself because the highway will not have to be fully or partly closed each time a large animal is struck. “If you shut clown Interstate 90, you shut down interstate trade. ” she adds.
1.What do we know about die I -90?
A. It goes from Washington D.C to Seattle,
B. It is dangerous for wild animals to cross.
C. It blocks the movements of wild animals.
D. It is the longest - ever highway in the world.
2.What is being done to help the animals?
A. Building a wildlife bridge to keep drivers and animals away.
B. Designing walls to protect animals from traffic accidents.
C. forming 2 arches, one for traffic and the other for animals.
D. Choosing a natural and safe area for wild animals to live in.
3.What can we learn from the study?
A. Traffic accidents went down gradually nationwide.
B. Most money was spent in rescuing wild animals,
C. Collisions are more deadly to wildlife than to people,
D. Some species no longer existed because of vehicle hits.
4.Which of the statements may Patty Garvey - Darda agree with?
A. The bridge costs too much money.
B. Animals won11 be struck by drivers.
C. The effort to build the bridge will pay off.
D. Collisions won't affect national trade at all.
In 2018 to which we've just said goodbye, we've seen excellent movies such as Black Panther, Crazy Rich Asians and A Star Is Born. In 2019 there will be returns to classic movie characters and stories. Here are movies not to miss.
Spider-Man-.Far H0- July 5, US
Tom Holland, the actor of 2017's Spider-Man: Homecoming, returns to play Peter Parker, a high school student who gains superpowers after being bitten by a spider(蜘蛛). When we see him again in theaters, Spider – Man will have a new red - and – black suit. The movie will take Peter on a global adventure outside of the US. According to Marved Studios President Kevin Feige, Spider - Man will try a return to his “normal" self; he will try to find his old powers on his new journey.
Hobbs and Shaw, July 26,US
To most people the Fast and Furious series is all about crazy drivers racing in sports car. But in Hobbs and Shaw, humor is added to the action - packed thrills. The new film will hit US theaters on July 26. Famous English actor Jason Statham will star alongside Dwayne Johnson, “The Rock”, as Deckaid Shaw and Luke Hobbs respectively, as in their previous appearances in Fast and Furious 8. The action and chemistry really thrill their audience. But the new action scenes between an MI6 agent Hobbs and the killer Shaw will have to be good to beat their stand - off in the 2017 movie.
The Lion King, July 19, US
This is a brand - new version of the classic children’s film. The story of wide - eyed young lion Simba still remains in hearts of world audiences even after 25 years. In this re-telling, Simba again begins the difficult journey to become the King of the Pride Lands，a vast African prairie(大草原).The favorite part of the story for many has always been the friendship between Simba, Timon and Punibaa. The last two sacrifice all they have to help Simba to become the king. How will the new movie re-imagine their famous relationship?
1.Which movie will probably be most popular among children?
A. Spider - Man: Far From Home. B. Hobbs and Shaw.
C. Fast and Furious 8. D. The Lion King.
2.What do the three movies have in common?
A. The heroes have appeared in previous movies.
B. They have the complex plot and humor style.
C. They will be on in theaters in July worldwide.
D. Famous actors and actresses act in the movies.
3.What’s the writing purpose of the text?
A. To ask for movie reviews.
B. To make comments on the movies.
C. To encourage readers to watch films
D. To instruct readers to know styles of movie.
听下面一段独白，回答以下小题。
1.Where is the speaker now?
A. In an office. B. In a clasroom. C. In a lab.
2.When does the course come during the first part of it?
A. On Tuesday and Thursday. B. On Tuesday and Friday.
C. On Thursday and Friday.
3.How often will the class meet in the research lab?
A. Once a week. B. Twice a week. C. Every two weeks.
4.What might be chosen to decide one’s final grade?
A. Role plays. B. Research papers. C. Class attendance.
听下面一段较长对话，回答以下小题。
1.What did Fred do last night?
A. He went to the police station.
B. He drove into a store and broke it up.
C. He went shopping with his girlfriend
2.Who did Fred have a fight with?
A. The storekeeper. B. The policeman. C. The girlfriend.
3.Where h Fred's car now?
A. In the store. B. In the street. C. In the police station.
