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共用题干
The Arctic Ice is Thawing
Father Christmas may have to move his"workshop"from the North Pole because global warming is
thawing the ice beneath his feet and his reindeers'feet as well.His"workshop"is in dire straits.The"plat-
form"for the"workshop"is melting,said Stefan Norris of the World Wildlife Fund environmental group's
Arctic Program.
An eight-nation report by 250 scientists published recently predicted the Arctic Ocean could be ice-free
in summer by 2100 because of a build-up of heat-trapping gases in the atmosphere,mainly from burning fossil
fuels in cars or factories.The North Pole is getting more and more uninhabitable to Father Christmas.
__________(46)Young people learn that Father Christmas'"workshop"produces millions of gifts delivered
by him on a flying,reindeer-drawn sleigh.Hollywood movies like"The Polar Express"tried to make viewers
believe that Father Christmas lives at the North Pole._______(47)
The"Fortress of Solitude"is near the North Pole that could be under threat in a warmer world. Alan Boldt,
spokesman of the Danish Ministry of Science,suggested ways to rescue Father Christmas._________(48)
Another alternative,he argued,woald be building some electrical facilities to ensure the ice stays on the North
Pole for him."This should be a subject for the United Nations,"he said."Danmark could build windmills to pro-
vide Father Christmas with power."Denmark says Father Christmas'real home is Greenland,which will help,
Denmark thinks,to strengthen its position in claiming the sovereignty over the Pole.__________(49)
"Doesn't he already speak Danish?"Boldt said frostily when asked if Father Christmas would be forced
to learn Danish if Denmark won international recognition of its claim to the Pole.Last month's Arctic report
said the region is warming twice as fast as the rest of the globe,partly because dark ground or water,once un-
covered,soaks up more heat than ice or snow.Finland has been most favored by Father Christmas and it has
about 500,000 tourists a year to visit its Christmas center in Rovaniemi in Lapland._________(50)
_________(49)
A:However,Nordic nations all reject it by claiming that their countries are his home.
B:Therefore the North Pole is the most attractive place in the world.
C:If Denmark's claim were accepted internationally,it would have the legal right to search for oil and gas at the North Pole.
D:One of them would be building a giant floating ice rink for the workshop if the Pole thaws.
E:Maybe Father Christmas has already moved to Rovaniemi.
F:He may have to move from the North Pole within our children's lifetimes.
You should have blended the butter with the sugar thoroughly before you heated them.
A:spread
B:mixed
C:beaten
D:covered
共用题干
“Liquefaction” Key to Much of Japanese Earthquake Damage
The massive subduction zone earthquake in Japan caused a significant level of soil“liquefaction” that has surprised researchers with its1severity,a new analysis shows.
“We've seen localized examples of soil liquefaction as extreme as this before,but the distance and2of damage in Japan were unusually severe,”said Scott Ashford,a professor of geotechnical engineering at Oregon State University.“Entire structures were tilted and sinking into the sediments,”Ashford said.“The shifts in soil destroyed water,drain and gas pipelines,crippling the utilities and infrastructure these communities need to3. We saw some places that sank as much as four feet.”
Some degree of soil liquefaction is common in almost any major earthquake. It's a phenomenon in which soils soaked with water,particularly recent sediments or sand,can lose much of their4and flow during an earthquake. This can allow structures to shift or sink or5.
But most earthquakes are much6than the recent event in Japan,Ashford said. The length of the Japanese earthquake,as much as five minutes,may force researchers to recon-sider the extent of liquefaction damage possibly occurring in situations such as this.
“With such a long-lasting earthquake,we saw7structures that might have been okay after 30 seconds just continued to sink and tilt as the shaking continued for several more minutes,”he said.“And it was clear that younger sediments,and especially areas built on8filled ground,are much more vulnerable.”
The data provided by analyzing the Japanese earthquake,researchers said,should make it possible to improve the understanding of this soil9and better prepare for it in the future.Ashford said it was critical for the team to collect the information quickly,10damage was removed in the recovery efforts.
“There's no doubt that we'll learn things from what happened in Japan that will help us to reduce risks in other similar11,”Ashford said.“Future construction in some places may make more use of techniques known to reduce liquefaction,such as better compaction to make soils dense,or use of reinforcing stone columns.”
Ashford pointed out that northern California have younger soils vulnerable to liquefac-tion一on the coast,near river deposits or in areas with filled ground. The“young”sedi-ments,in geologic terms,may be those12within the past 10,000 years or more. In Ore-gon,for instance,that describes much of downtown Portland,the Portland International Airport and other cities.
Anything13a river and old flood plains is a suspect,and the Oregon Department of Transportation has already concluded that 1,100 bridges in the state are at risk from an earthquake.
Fewer than 15 percent of them have been reinforced to14collapse. Japan has suffered tremendous losses in the March 11 earthquake,but Japanese construction15 helped prevent many buildings from collapse一even as they tilted and sank into the ground.
10._________
A: unless
B: until
C: after
D: before
共用题干
Earth Rocks on
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'ye 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 asteroids(小行星)were hitting Earth,keeping its crust in
a hot,melted state.After the hard crust formed,much of it sank at various times into the planet's hot in-
sides.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 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 , called magma(岩浆),flowed up slowly 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.
The shape of lands and oceans are slowly changed with the movements of plates.
A:Right
B:Wrong
C:Not mentioned
共用题干
The Greatest Mystery of Whales
The whale is a warm-blooded,air-breathing animal,giving birth to its young alive,sucking them-and, like all mammals,originated on land.There are many______(51)of this.Its front flippers(鳍状肢), used for steering and stability,are traces of feet.
Immense strength is______(52)into the great body of the big whales,and in fact most of a wha'e'sbo衡is one gigantic muscle.The blue whale's pulling strength has been estimated______(53) 400 horsepower.One specimen was reported to have towed(拖)a whaling vessel for seven hours at the______ (54)of eight knot(节).
An angry whale will______(55).A famous example of this was the fate of Whaler Essex,______(56)was sunk off the coast of South America early in the last century.More recently,steel ships
have ___________( 57 ) their plates buckled(使弯曲)in the same way.Sperm whales(抹香鲸)were known to seize the old-time whaleboats in their jaws and crush them.
The greatest______(58)of whales is their diving ability.The sperm whale dives to the bottom for his ______(59)food,the octopus(章鱼).In that search he is known to go as far down as 3,200 feet,where the ______(60)is 1 ,400 pounds to a square inch.Doing so he will______(61)underwater as long as one hour.Two special1 skills are involved in this storing up enough______(62)(all whales are air-breathed ) and tolerating the great change in pressure.Just how he does it scientists have not______(63).It is believed that some of the oxygen is stored in a special______(64)of blood vessels,rather than just held in the lungs.And it is believed that a special kind of oil in his head is some sort of a compensating mechanism that ______(65)adjusts the internal pressure of his body.But since you can't bring a live whale into the laboratory for study,no one knows just how these things work.
65._________
A:mentally
B:artificially
C:manually
D:automatically