选择知识点

[Washington， 16 April 2009] President Barack Obama wants the United State to join other industrialized countries in having an extensive high-speed rail system． The president has announced his plan to accelerate the development of high-speed rail in the U．S．
President Obama says high-speed rail could do for America what it is already doing for other countries， including China and Spain． "A high-speed line between Madrid and Seville is so successful that more people travel between those cities by rail than by car and airplane combined． China， where service began just two years ago， may have more miles of high-speed rail service than any other country just five years from now，" he said．
High-speed rail only serves America's Northeast corridor， between Washington， D．C． and Boston， Massachusetts． But plans are under way to extend the rapid movement to other areas of the country．
Before leaving for Latin America， Mr． Obama outlined his two-part strategy for accelerating those plans． "Improving our existing rail lines， to make current train service faster， but also identifying potential corridors for the creation of world-class high-speed rail，" he said．
Congress included ﹩8 billion for rail development in the economic stimulus（刺激）legislation it passed in February．Mr．Obamais including another﹩5 billion for high-speed rail in his federal budget． High-speed rail has had mixed political support in the past． But President Obama says it could strengthen the US． economy， in addition to improving the country's transportation system． He says the United States should not be left behind while other nations are moving ahead with high-speed rail．
"So it is being done． It is just not being done here． There is no reason why we cannot do this． This is America． There is no reason why the future of travel should lie somewhere else， beyond our borders，" he said．
The president was joined at the announcement by Vice President Joe Biden， who， in 35 years at a U．S． Senator， is said to have taken almost 8.000 rail trips between Washington and his home in Willington， Delaware．



In Spain， more people would ______ if they traveled from Madrid to Seville．

A. take the rail
B. drive their cars
C. go by air
D. ride their bikes

Which of the following is true to the passage？ ______

A. High-speed rail is doing a lot for America．
B. High-speed rail is already doing much for Spain．
C. Now China has many more miles of high-speed rail service than any other country．
D. President Obama wants to change the situation that America has no high-speed rail service．

Obama's plans of extensive high-speed rail system include the following except ______ ．

A. improving America's existing rail line
B. creating its high-speed rail system of world class
C. making its current train service faster
D. strengthening America's economy

When Obama announced this plan， Vice President Joe Biden ______ ．

A. had taken his trip back home in Wilmington， Delaware
B. was leaving for Latin America
C. was on holiday in Boston， Massachusetts
D. was right present in Washington

Top branded perfumes come in tiny bottles，but many hide a whale sized secret．
To perfect a particular smell，perfume makers often use an ingredient that comes from sperm whales （抹香鲸），called ambergris．But using ambergris，which helps a perfume last longer，is strongly opposed by many people who think it is wrong to kill whales just so we can smell sweet．Joerg Bohlmann is neither a perfumer nor a whale expert．He's a plant biologist at the University of British Columbia in Canada．But his discovery of a new plant gene might push whales out of the perfume business．
The gene comes from fir trees，found throughout North America and commonly used as Christmas trees．The trees produce a chemical that can be used in perfume in place of ambergris-but with a catch．
"There's a problem that many people wouldn't consider．In the tree，the chemical is mixed with many others．That makes separation a challenge"Bohlmann says．"It's like trying to isolate sugar from a biscuit．"
This is where science becomes useful．When Bohlmann learned that fir trees produce the ambergris-like chemical，he decided to use his gene know-how to find the instructions for how to make the ambergris substitute．
Bohlmann found that gene and took it out of the tree cells．Then he did something that might sound strange to someone who doesn't work in genetics：Bohlmann put the gene from the tree into yeast （酵母） cells．
Yeast may sound familiar because it's used to make things like bread，wine and beer．Biologists like to work with yeast because it easily adopts new genes and changes its features and behavior．When Bohlmann put the fir tree gene into the yeast，the yeast started making the same chemical that had been produced by the tree．
Perfumers pay big money for ambergris because it is a fixative，which means it holds a smell in place on a person's body．
"Cheap perfumes smell good in the first hour or so and then everything is gone，"explains Bohlmann．"But expensive perfumes are much more stable．Their smell lasts much longer，for hours or even a day after you apply them．"
The new chemical，made from the tree genes，can be used as a fixative，too．And using yeast to make it is far cheaper than acquiring ambergris．
Bohlmann admits he never thought he'd get into the perfume business．But now，he says，producers have been calling to find out how to use his technology in new perfumes．



It can be inferred from the passage that if a perfume contains ambergris， ______ ．

A. it is probably very expensive
B. its smell will last for about an hour
C. there will be a whale symbol on the bottle
D. its user probably supports whale hunting

The underlined expression"with a catch"in Paragraph 3means ______ ．

A. being difficult to hold
B. being too similar
C. needing further testing
D. having a hidden problem

According to the passage，why are yeast cells often used in genetic research？ ______

A. They share some of the qualities of plant genes．
B. They can take on the characteristics of other genes．
C. They can reproduce much faster than other cells．
D. They're much cheaper to use than ambergris．

What is the best title for the passage？ ______

A. The Christmas tree's secret．
B. The sweet smell of success．
C. Whale free perfume．
D. Save the whale．