40. Questions 36 to 40 are based on the following passage.Some people have said aging is more a slide into forgetfulness than a journey towards wisdom.However， a growing body of research suggests that late-in-life learning is possible.In reality， education does an aging brain good.Throughout life， people’s brains constantly renovate themselves.In the late 1960s， British brain scientist Geoffrey Raisman spied growth in damaged brain regions of rats through an electron microscope; their brains were forging new connections.This meant brains may change every time a person learns something new.Of course， that doesn’t mean the brain isn’t affected by the effects of time.Just as height usually declines over the years， so does brain volume: Humans lose about 4 percent every decade starting in their 40s.But that reduction doesn’t necessarily make people think slower; as long as we are alive and functioning， we can alter our brains with new information and experiences.In fact， scientists now suspect accumulating novel experiences， facts， and skills can keep people’s minds more flexible.New pathways can strengthen our ever-changing mental structure， even as the brain shrinks.Conventional fixes like word puzzles and brain-training apps can contribute to mental durability.Even something as simple as taking a different route to the grocery store or going somewhere new on vacation can keep the brain healthy.A desire for new life challenges can further boost brainpower.Research about aging adults who take on new enterprises shows improved function and memory as well as a reduced risk of mental disease.Openness—a characteristic defined by curiosity and a desire for knowledge—may also help folks pass brain tests.Some folks are born with this take-in-the world attitude， but those who aren’t as genetically gifted aren’t necessarily out of luck.While genes can encourage an interest in doing new things， a 2012 study in the journal Psychology and Aging found completing reasoning tasks like puzzles and number games can enhance that desire for novel experiences， which can， in turn， refresh the brain.That’s why brain scientist Richard Kennedy says “It’s not that old dogs can’t learn new tricks.It’s that maybe old dogs don’t realize why they should.”What is the finding of the 2012 study in the journal Psychology and Aging?

4. Passage Thirty-TwoHave you ever heard of a pawpaw (木瓜)? If not， do not feel bad.Many Americans do not know of the fruit， although it is native to the U.S.Once， however， it was one of the most popular fruits in North America.Happily， those who love the pawpaw are trying to return it to its former position in American foods.A pawpaw is a tropical fruit that used to be grown along the East Coast from New York to Florida and all over the eastern U.S.At one time， it could be found as far west as Nebraska.The pawpaw was an important food for Native Americans and even early European settlers.Pawpaws reportedly were a favorite treat of George Washington， the first U.S.president， who especially liked them cold.Thomas Jefferson， the third U.S.president， was also a fan of the fruit.He planted pawpaws at his home in Virginia.He also sent pawpaw seeds to his friends in France.American explorers Lewis and Clark wrote in their journals about the pawpaw.The pawpaw is difficult to be sold commercially.The fruit requires a very special environment—low， wet areas that sometimes flood.It has a very short harvest season， from two to three weeks in September and October.In addition， the fruit is good to eat for only two to three days after harvesting.This makes it hard to sell anywhere distant from the pawpaw tree it comes from.Planters are again growing pawpaw trees and harvesting the fruit.In several states farmers have organized “pawpaw festivals” to reintroduce people to food.At such a festival in Maryland recently， farmers displayed different products made with pawpaws， like pawpaw jams， pies， ice-cream and beer.It is difficult to sell the pawpaw on a large scale for the following reasons EXCEPT that the fruit ().

3. Passage Thirty-TwoHave you ever heard of a pawpaw (木瓜)? If not， do not feel bad.Many Americans do not know of the fruit， although it is native to the U.S.Once， however， it was one of the most popular fruits in North America.Happily， those who love the pawpaw are trying to return it to its former position in American foods.A pawpaw is a tropical fruit that used to be grown along the East Coast from New York to Florida and all over the eastern U.S.At one time， it could be found as far west as Nebraska.The pawpaw was an important food for Native Americans and even early European settlers.Pawpaws reportedly were a favorite treat of George Washington， the first U.S.president， who especially liked them cold.Thomas Jefferson， the third U.S.president， was also a fan of the fruit.He planted pawpaws at his home in Virginia.He also sent pawpaw seeds to his friends in France.American explorers Lewis and Clark wrote in their journals about the pawpaw.The pawpaw is difficult to be sold commercially.The fruit requires a very special environment—low， wet areas that sometimes flood.It has a very short harvest season， from two to three weeks in September and October.In addition， the fruit is good to eat for only two to three days after harvesting.This makes it hard to sell anywhere distant from the pawpaw tree it comes from.Planters are again growing pawpaw trees and harvesting the fruit.In several states farmers have organized “pawpaw festivals” to reintroduce people to food.At such a festival in Maryland recently， farmers displayed different products made with pawpaws， like pawpaw jams， pies， ice-cream and beer.George Washington and Thomas Jefferson are mentioned in paragraph 3 as ().

2. Passage Thirty-TwoHave you ever heard of a pawpaw (木瓜)? If not， do not feel bad.Many Americans do not know of the fruit， although it is native to the U.S.Once， however， it was one of the most popular fruits in North America.Happily， those who love the pawpaw are trying to return it to its former position in American foods.A pawpaw is a tropical fruit that used to be grown along the East Coast from New York to Florida and all over the eastern U.S.At one time， it could be found as far west as Nebraska.The pawpaw was an important food for Native Americans and even early European settlers.Pawpaws reportedly were a favorite treat of George Washington， the first U.S.president， who especially liked them cold.Thomas Jefferson， the third U.S.president， was also a fan of the fruit.He planted pawpaws at his home in Virginia.He also sent pawpaw seeds to his friends in France.American explorers Lewis and Clark wrote in their journals about the pawpaw.The pawpaw is difficult to be sold commercially.The fruit requires a very special environment—low， wet areas that sometimes flood.It has a very short harvest season， from two to three weeks in September and October.In addition， the fruit is good to eat for only two to three days after harvesting.This makes it hard to sell anywhere distant from the pawpaw tree it comes from.Planters are again growing pawpaw trees and harvesting the fruit.In several states farmers have organized “pawpaw festivals” to reintroduce people to food.At such a festival in Maryland recently， farmers displayed different products made with pawpaws， like pawpaw jams， pies， ice-cream and beer.The pawpaw used to be found mainly ().

1. Passage Thirty-TwoHave you ever heard of a pawpaw (木瓜)? If not， do not feel bad.Many Americans do not know of the fruit， although it is native to the U.S.Once， however， it was one of the most popular fruits in North America.Happily， those who love the pawpaw are trying to return it to its former position in American foods.A pawpaw is a tropical fruit that used to be grown along the East Coast from New York to Florida and all over the eastern U.S.At one time， it could be found as far west as Nebraska.The pawpaw was an important food for Native Americans and even early European settlers.Pawpaws reportedly were a favorite treat of George Washington， the first U.S.president， who especially liked them cold.Thomas Jefferson， the third U.S.president， was also a fan of the fruit.He planted pawpaws at his home in Virginia.He also sent pawpaw seeds to his friends in France.American explorers Lewis and Clark wrote in their journals about the pawpaw.The pawpaw is difficult to be sold commercially.The fruit requires a very special environment—low， wet areas that sometimes flood.It has a very short harvest season， from two to three weeks in September and October.In addition， the fruit is good to eat for only two to three days after harvesting.This makes it hard to sell anywhere distant from the pawpaw tree it comes from.Planters are again growing pawpaw trees and harvesting the fruit.In several states farmers have organized “pawpaw festivals” to reintroduce people to food.At such a festival in Maryland recently， farmers displayed different products made with pawpaws， like pawpaw jams， pies， ice-cream and beer.Many American people do not know that the pawpaw ().

5. Passage Thirty-OneAdam Smith was the first person to see the importance of the division of labor.He gave us an example of the process by which pins were made in England.“One man draws out the wire， another strengthens it， a third cuts it， a fourth points it， and a fifth gives it a head.Just to make the head requires two or three different operations.The work of making pins is divided into about eighteen different operations， which in some factories are all performed by different people， though in others the same man will sometimes perform two or three of them.”Ten men， Smith said， in this way， turned out twelve pounds of pins a day or about 4，800 pins a worker.But if all of them had worked separately and independently without division of labor， they certainly could not have made twenty pins in a day and not even one.There can be no doubt that division of labor is an efficient way of organizing work.Fewer people can make more pins.Adam Smith saw this， but he also took it for granted that division of labor is itself responsible for economic growth and development and it accounts for the difference between expanding economies and those that stand still.But division of labor adds nothing new， it only enables people to produce more of what they already have.According to the writer， which of the following is NOT true?

4. Passage Thirty-OneAdam Smith was the first person to see the importance of the division of labor.He gave us an example of the process by which pins were made in England.“One man draws out the wire， another strengthens it， a third cuts it， a fourth points it， and a fifth gives it a head.Just to make the head requires two or three different operations.The work of making pins is divided into about eighteen different operations， which in some factories are all performed by different people， though in others the same man will sometimes perform two or three of them.”Ten men， Smith said， in this way， turned out twelve pounds of pins a day or about 4，800 pins a worker.But if all of them had worked separately and independently without division of labor， they certainly could not have made twenty pins in a day and not even one.There can be no doubt that division of labor is an efficient way of organizing work.Fewer people can make more pins.Adam Smith saw this， but he also took it for granted that division of labor is itself responsible for economic growth and development and it accounts for the difference between expanding economies and those that stand still.But division of labor adds nothing new， it only enables people to produce more of what they already have.According to the writer， Adam Smith’s mistake was in believing that the division of labor ().

3. Passage Thirty-OneAdam Smith was the first person to see the importance of the division of labor.He gave us an example of the process by which pins were made in England.“One man draws out the wire， another strengthens it， a third cuts it， a fourth points it， and a fifth gives it a head.Just to make the head requires two or three different operations.The work of making pins is divided into about eighteen different operations， which in some factories are all performed by different people， though in others the same man will sometimes perform two or three of them.”Ten men， Smith said， in this way， turned out twelve pounds of pins a day or about 4，800 pins a worker.But if all of them had worked separately and independently without division of labor， they certainly could not have made twenty pins in a day and not even one.There can be no doubt that division of labor is an efficient way of organizing work.Fewer people can make more pins.Adam Smith saw this， but he also took it for granted that division of labor is itself responsible for economic growth and development and it accounts for the difference between expanding economies and those that stand still.But division of labor adds nothing new， it only enables people to produce more of what they already have.Adam Smith mentioned the number 4，800 in order to ().

2. Passage Thirty-OneAdam Smith was the first person to see the importance of the division of labor.He gave us an example of the process by which pins were made in England.“One man draws out the wire， another strengthens it， a third cuts it， a fourth points it， and a fifth gives it a head.Just to make the head requires two or three different operations.The work of making pins is divided into about eighteen different operations， which in some factories are all performed by different people， though in others the same man will sometimes perform two or three of them.”Ten men， Smith said， in this way， turned out twelve pounds of pins a day or about 4，800 pins a worker.But if all of them had worked separately and independently without division of labor， they certainly could not have made twenty pins in a day and not even one.There can be no doubt that division of labor is an efficient way of organizing work.Fewer people can make more pins.Adam Smith saw this， but he also took it for granted that division of labor is itself responsible for economic growth and development and it accounts for the difference between expanding economies and those that stand still.But division of labor adds nothing new， it only enables people to produce more of what they already have.Adam Smith saw that the division of labor ().

1. Passage Thirty-OneAdam Smith was the first person to see the importance of the division of labor.He gave us an example of the process by which pins were made in England.“One man draws out the wire， another strengthens it， a third cuts it， a fourth points it， and a fifth gives it a head.Just to make the head requires two or three different operations.The work of making pins is divided into about eighteen different operations， which in some factories are all performed by different people， though in others the same man will sometimes perform two or three of them.”Ten men， Smith said， in this way， turned out twelve pounds of pins a day or about 4，800 pins a worker.But if all of them had worked separately and independently without division of labor， they certainly could not have made twenty pins in a day and not even one.There can be no doubt that division of labor is an efficient way of organizing work.Fewer people can make more pins.Adam Smith saw this， but he also took it for granted that division of labor is itself responsible for economic growth and development and it accounts for the difference between expanding economies and those that stand still.But division of labor adds nothing new， it only enables people to produce more of what they already have.According to the passage， Adam Smith was the first person to ().

5. Passage ThirtyThe Chinese have used a method called acupuncture (针灸)to help perform operations for about 4， 000 years without putting the patient to sleep.This involves inserting flexible needles into certain parts of the body.The needles are available in a number of stores in China and everyone may buy them.To learn how to use needles takes about one month of training.But to be skillful requires greater time.The person who performs the acupuncture knows how to put in the needles so the needles themselves are not painful.This person also knows where to place the needles so the patient feels no pain in the area where the operation is to be performed.In the past， a particular operation might require 25 or more needles placed in various parts of the body.But now this operation requires only 3 or 4 needles.Today， the Chinese doctors are trying to learn more about acupuncture.They are trying to develop a convincing theory to explain how the needles work in preventing pain， or why a needle in the wrist， for example， would prevent the pain in the area of the mouth.A patient who needs an operation is given a choice between having acupuncture or having one of the chemicals used for putting him to sleep.It has been estimated that over half of the patients choose acupuncture because there is no sickness after the operation whereas the chemical may make the patient sick for a few hours or a day.Which is implied but NOT stated in the passage?