"The world's oceans are slowly getting more acidic,”say scientists. The researchers from California report that the change is taking place in response to higher levels of carbon dioxide in the atmosphere.
The lowering of the waters’pH value is not great at the moment but could cause a serious threat to current ocean life if it continues, they warn. Ken Caldeira and Michael Wickett, from the Lawrence Livermore National Laboratory, report their concerns in the journal Nature.
Increasing use of oil fuels means more carbon dioxide is going into the air, and most of it will eventually be absorbed by seawater. Once in the water, it reacts to form carbonic acid. Scientists believe that the oceans have already become slightly more acidic over the last century.
These researchers have tried to predict what will happen in the future by combining what we know about the history of the oceans with computer models of climate change．"This level of acidity will get much more extreme in the future if we continue releasing CO2 into the atmosphere," said Dr Caldeira. "And we predict the amount of future acidity will exceed（超过）anything we have seen over the last several hundred million years, let alone perhaps after rare disastrous events such as asteroid（小行星) impacts．”
However, it is not absolutely clear what that means for ocean life．Most organisms live near the surface, where the greatest pH change would be expected to occur, but deep-ocean life forms may be more sensitive to pH changes．Coral reefs and other organisms whose shells contain calcium carbonate（小行星) may be particularly affected if the water's acidity levels keep going up, the team predict. They could find it much more difficult to build these structures in water with a lower pH.
In recent years some people have suggested storing carbon dioxide from power stations in the deep ocean as a way of dealing with global warming．But Dr Caldeira said that such a strategy should now be re-considered. "Previously, most experts had looked at ocean absorption of carbon dioxide as a good thing-because in releasing CO2 into the atmosphere we warm the planet, and when CO2, is absorbed by the ocean, it reduces the amount of greenhouse warming.”According to Dr Caldeira,__________ .
| A．ocean absorption of carbon dioxide is a good thing |
| B．more oil fuels will be used in the near future |
| C．scientists may predict climate changes with computer models |
| D．the future situation of the amount of acidity is extremely serious |
f the water's acidity level keeps rising,_________ .
| A．ocean life whose structures contain calcium carbonate may be affected |
| B．the waters’pH value will become higher and higher |
| C．organisms living near the surface are more sensitive to pH changes |
| D．some disastrous events will occur more often than before |
Most experts once believed storing carbon dioxide in the ocean would reduce________ .
| A．the CO2 absorbed by the ocean | B．the amount of greenhouse warming |
| C．the acidity of the ocean | D．the gradual release of CO2 |
The purpose of this passage is to_________ .
| A．show people the findings of a research team | B．inform people of how acid the ocean is now |
| C．introduce Dr Caldeira and his team's research | D．warn people of the higher level of CO2 |
Ted Shreds doesn't like cars.He wants people to stop driving because cars make the air dirty.Ted had an idea.He said,“I'm going to cycle around North America.I want to show everyone that cycling is a fun way to get around.If more people ride bikes,the air will be cleaner.”
He left his hometown with $160 in his pocket.When he got to San Diego,he met another cyclist.The cyclist invited Ted to speak at a big meeting about the environment.He said,“We'll pay your airfare to Texas and we'll pay you to talk about your cycling trip.”Two hours late,Ted was on a plane to the environmental conference and to a big surprise!
While he was at the conference,he met Deanna,it was love at first sight!They talked for six hours straight.
The next day,Ted called Deanna and asked her to finish the trip with him.Deanna said yes,sold everything in her apartment,gave her notice at work,and was on the road with Ted 20 days later!
“It was difficult at first,”said Deanna.“Ted got up every morning at 6:00 a.m.,but I wanted to sleep until noon.”After a few days,they started having fun.As they cycled from Florida to Montreal and then back to Vancouver,every day was an adventure.People paid for their food in restaurants and gave them extra money.Some people gave them $50 or $100.They slept in people's backyards and drank beer with motorcycle gangs.
On their way back to Vancouver,they stopped in Edmonton to visit Ted's relatives.During the stopover,they got married.People tied a “Just Married” sign and tin cans to the backs of their bikes.They got married.They now want to write a book about their trip.“We want people to know that you can be an environmentalist and still have fun,”Shreds said.Ted Shreds went cycling because_________.
| A．he loves adventure |
| B．cycling is a lot of fun |
| C．he wanted to find himself a wife |
| D．he supports environmental protection |
Ted got paid for_________.
| A．giving a talk about his cycling trip | B．cycling throughout North America |
| C．traveling around North America by air | D．attending conferences on cycling |
The “big surprise” he had at the conference was that _________.
| A．he met another cyclist who wanted to join him |
| B．he fell in love with a girl there |
| C．he gave a long talk lasting 6 hours |
| D．he had a lot of fun talking about his cycling trip |
During the trip,Ted and Deanna_________.
| A．found it hard to get up early |
| B．were attacked by motorcycle gangs |
| C．did not have to pay for their meals in restaurants |
| D．decided to get married |
How many coins have you got in your pocket right now?Three?Two?Or one?With a phonecard you can make up to 200 calls without any change at all.
1.What do you do with it?
Go to a telephone box marked “Phonecard”.Put in your card,make your call and when you've finished,a screen tells you how much is left on your card.It costs no extra for the cards,and the calls cast 10 per unit,the same as any other payphone call.You can put them in units of 10,20,40,100 or 200.
2.Now appearing in a shop near you
Near each card phone place you'll find a shop where you can buy one.They're at bus,train and city tube stations.Many universities,hospitals and clubs,restaurants and gas stations on the highway and shopping centers.At airports and seaports.
3.No more broken payphones
Most broken payphones are like that they've been vandalized（破坏了的）.There are no coins in Cardphone to excite thieves' interest in it.So you're not probably to find a vandalized one.Get a phonecard yourself and try it out.Or get a bigger wallet.There are three sections in the passage.Which section do you think is about why phonecards are good?
| A．Section 1. | B．Section 2. | C．Section 3. | D．Section 1&2. |
Choose the right order of the steps under“How to use a phonecard”.
a.Put in your phonecard.
b.Look at the screen to find out how many calls you can still make.
c.Go to a telephone box marked “Phonecard”.
d.Make your call.
| A．a,b,c,d | B．c,a,d,b | C．a,d,c,b | D．c,d,a,b |
The last sentence “Or get a bigger wallet”means“_________”.
| A．Phonecards are cheap |
| B．You cannot use all payphones |
| C．Thieves will not break card phones |
| D．People do not like carrying a lot of coins |
Bill Clinton was born on Aug.19,1946.Three months before his birth,his father had died when driving home to his pregnant wife,Virginia,he went off a high way,was thrown from the car and drowned in a river.
When Bill was 4,his mother remarried Roger Clinton.And there were always troubles:a sometimes voilent,alcoholic stepfather and a half-brother.Only one year after the marriage,the drunken stepfather fired a shotgun at the ceiling to keep his bride and stepson from leaving the house.Virginia was very much frightened.So Roger Clinton beat Virginia from time to time.But teenager Clinton played a role of protector of his mother bravely.The stepfater never laid another band on Virginia.
In high school,he was very good at Latin and maths.He also played saxophone in the hand.At age 16,as a member of a youth group,Clinton met President John F.Kennedy at the White House,it led him to the life of public service.Once he set his mind to do something,he did not give up.He was elected governor of Arkansas at the age of 32.
Clinton has said he ran for president to make the country a better place for people like Chelsea,his daughter.He did win.At the age of 46,he became the third youngest president in the nation's history.When this passage was published,Clinton was_________.
A.governor of Arkansas B.a famous professor
C.President of U.S.A. D.President of a universityClinton's own father died_________.
| A．before Clinton was born |
| B．after Clinton was born |
| C．from drinking too much brandy |
| D．when Clinton's mother was giving birth |
Clinton protected his mother by_________.
| A．fighting against his stepfather |
| B．beating his stepfather |
| C．having long talks with his stepfather |
| D．the means we don't know |
The word “it” in “It led him to the life of public service”refers to_________.
| A．Clinton's high school education |
| B．becoming a member of a youth group |
| C．Clinton's visiting President Kennedy |
| D．doing public service |
Americans have contributed to many art forms,but jazz,a type of music,is one of the art forms that was started in the United States.Black Americans,who sang and played the music of their homeland,created jazz.
Jazz is a mixture of the music of Africa,the work songs the slaves sang,and religious（宗教）music.Improvisation is an important part of jazz.This means that the musicians make the music up as they go along,or create the music on the spot.This is why a jazz song might sound a little different each time it is played.
Jazz bands formed in the late 1800s.They played in bars and clubs in many towns and cities of the South,especially New Orleans.New Orleans is an international seaport,and people from all over the world come to New Orleans to hear jazz.
Jazz became more and more popular.By the 1920s,jazz was popular all over the United States.By the 1940s,you could hear jazz not only in clubs and bars,but in concert halls as well.Today,people from all over the world play jazz.Jazz musicians from the United States,Asia,Africa,South America,and Europe meet and share their music at festivals on every continent.In this way jazz continues to grow and change.What can be the best title of the passage?
| A．American Art Forms | B．The Development of Jazz |
| C．The Music of Black Americans | D．The Birthplace of Jazz |
Which of the following is TRUE?
| A．Jazz is now popular all over the world. |
| B．Jazz is now a kind of religious music. |
| C．Jazz is now played only in bars and clubs. |
| D．Jazz is now played a little differently sometimes. |
From the text it can be inferred that_________.
| A．New Orleans is the place where jazz was first produced |
| B．the American people are all jazz lovers |
| C．jazz is merely sung by the black when working |
| D．jazz may become more popular as time goes on |
It took about _________ years to make jazz popular in the United States.
| A．200 | B．120 | C．80 | D．40 |
Snow-melting Agent
A heavy snow can kill pests and this means a good harvest next year.This will bring as well as trouble to urbanites.
On Nov.16,2003,a cold air current brought a heavy snow to Beijing.To prevent traffic jams,related government departments mobilized people to clear off snow on streets.
One of the most effective ways to clear off snow on roads is to scatter snow-melting agent on the roads.The major component of the snow-melting agent is salt.The snow-melting agent can make snow stop from freezing,make it easier to clear off the road,and allow traffic to flow smoothly.But it also brings about some hidden dangers.In the spring of 2003,over 300 000 trees in Beijing urban districts died.After analyzing soil around these trees,experts discovered that the salt content of these soils was 392 times higher than normal.Where did the excessive salt come from?After investigating,forestry experts found that when clearing snow in the winter,people usually heap snow containing snow-melting agent at trees’ roots,and that when the snow melts,this agent penetrates the soil and increases its salt content.The snow-melting agent indirectly killed the trees.
Statistics show that during a heavy snow in 2002,over 1000 tons of snow-melting agent was scatterred on streets in Beijing.Snow water containing a large amount of snow-melting agent got into the soil through sewers.
In addition,salt in the snow-melting agent can expedite the corrosion of steel bars in concrete buildings and cause the concrete to crack and peel,shortening the life of roads.
Scientists and government officials are required to solve traffic problems caused by heavy snows as soon as possible and at the same time try to reduce the negative effects of the snow-melting agent.This is a difficult problem placed before them.Related authorities have framed some local criteria to regulate the production and use of snow-melting agents.
Now,more harmless snow-melting agents are being developed.Now that even snow-melting agents that meet today’s criteria must still be used carefully,we have to rely more on our manpower and machines to clear off snow.
This year,in addition to using snow-melting agents,Beijing will use a large number of snow vehicles to clear snow on roads.In more places,citizens are mobilized to clear snow with their hands.This may be a test of a city’s civilization level.Salt is a snow-melting agent while _________ is a cleaning agent.
| A．water | B．soap | C．a washing-machine | D．a housewife |
The third paragraph of the text is mainly about _______.
| A．the side effect of snow-melting agent |
| B．a case of damage to trees caused by snow-melting agent |
| C．the results of using snow-melting agent |
| D．the uses of snow-melting agent |
According to the text,the most practical way to clear off snow is to _________.
| A．use snow-melting agent as much as possible |
| B．only use more harmless snow-melting agent |
| C．encourage people to clear snow with their hands |
| D．use more snow vehicles |
This text most probably appears in_________.
| A．a newspaper | B．a magazine on latest findings |
| C．a book on salt | D．a magazine on environmental protection |