Dye (染料) can bring a little color to life. Most clothing is colored with dyes. Modern, manufactured dyes can be costly. Natural dyes from plant and animal products have been used since ancient times. So this week, we describe a natural way to dye wool.

There are several methods to put dye onto material. The vat method, for example, can be used to dye wool with onionskins. For this example, use one hundred grams of natural wool. The wool must be clean. Leave it overnight in water and liquid soap. Then wash it with clean water that is a little warm. Gently squeeze out the extra water.

A solution called a mordant (媒染) is used in the dying process. A mordant helps fix the dye to the material. Traditionally, mordants were found in nature. Wool ash is one example. But chemical mordants such as alum are popular today. Alum is sold in many stores. It is often mixed with cream of tartar, a fine powder commonly used in cooking.

Mix eight grams of alum with seven grams of cream of tartar in a small amount of hot water. Add the solution to a metal pan of cool water. Next, add the wool and place the mixture over heat. Slowly bring the liquid to eighty-two degrees Celsius. Heat the mixture for forty-five minutes. After it cools, remove the wool and wash it.

To prepare the dye solution, cover thirty grams of onionskins with water. Use only the dry, brown outer skins. Boil the liquid until the onionskins lose their color, about forty-five minutes. Remove the skins after the dye cools.

Now it is time to dye the wool. Place the wool into the dye and heat the mixture. Bring it to a boil, then immediately reduce the heat to eighty-two degrees. Now heat the dye for about forty-five minutes or until the wool is the desired color. Keep in mind that wet wool looks darker than it is.

Once the dye cools, remove the wool and wash it. Now the wool is orange or yellow. Or at least it should be.

57. According to the passage, mordants are ________.

A. dyes used in the dying process

B. materials which will be put dye to

C. wood ashes used in the dying process

D. not dyes but play an important role in the dying process

58. Which of the following statements about “natural dyes” is true?

A. They might be cheaper than chemical dyes.

B. They are more expensive than chemical dyes.

C. They have been used for only recent years.

D. They are all made from animal products.

59. As for the vat method, which of the following statements is NOT necessarily needed?

A. Ash.                B. Water.           C. Mordant.              D. Temperature.

60. Choose the proper order of dying wool:

a. boil the liquid with onionskins.

b. add mordants to a metal pan of cool water.

c. wash the wool with clean water.

d. put the wool into the liquid and heat it

e. heat the mixture and then wash it.

A. c, b, e, a, d        B. e, b, c, d, a     C. b, e, a, d, c              D. a, b, e, c, d

In South America, the rich soil of the Amazon River basin（流域）in Brazil is known as “black gold”. Scientists found that the secret of this rich soil was charcoal（木炭）. Local people made it from animal bones and tree branches. They mixed the charcoal with the soil about 1.500 years ago.

Now, scientists in the United States have done a modern demonstration. They say charcoal fertilization offers a revolutionary way to improve soil quality for hundreds or even thousands of years.

Mingxin Guo and his team at Delavare State University heated tree leaves, corn stalks（茎）, small pieces of wood and poultry waste into “biochar”（生物碳）. They reported their findings at a recent meeting of the American Chemical Society in New Orleans.

Biochar could be good news for farmers with poor soil and hungry populations to feed. Professor Guo says it could even help against global warming. Intensive（集约的） farming and overuse of chemical fertilizer give out carbon dioxide into the atmosphere. Biochar does the opposite, he says. It traps carbon in the ground.

The researchers planted winter wheat in containers of soil in a greenhouse — some with biochar, some without. Professor Guo says the wheat grows much better in the pots with biochar. The soil was added two percent charcoal to. But he says even a one percent treatment will increase productivity.

The results demonstrated that biochar can increase organic matter in soil. Loss of nutrients in soil is an increasing problem worldwide as farmers try to grow more food for growing populations.

Next, the team will carry out a five-year study of biochar with spinach（菠菜）, green peppers and tomatoes.

Mingxin Guo says he learns about the “black gold” in Brazil from a magazine story. He explains that it was discovered in the jungle, in the area where waters flow to the Amazon, in the 1960’s. But it was not until recent years that scientists began to bring public attention to it.

1.According to the passage, which of the following statements is TRUE?

A．The researchers will go on proving their theory.

B．The leading researcher learns the theory from the magazine.

C．Charcoal was discovered 1,500 years ago.

D．Common farming can produce more carbon dioxide.

2.Biochar has the following advantages EXCEPT that ________.

A．it can improve the condition of the soil       

B．it can be used as a kind of energy

C．it can help against global warming 

D．it can increase productivity of the corn

3.According to the research, the biochar can help against global warming because it can ________.

A．reduce the carbon dioxide

B．keep the carbon in the soil

C．reduce the loss of nutrients in the soil

D．absorb the carbon dioxide

4.Which of the following can be the best title of the passage?

A．Using Charcoal to Make soil into “Black Gold”

B．Using Charcoal to Reduce the Carbon Dioxide

C．How Amazon River Basin Produces “Golden Black”

D．Guo’s Research on Producing Biochar

Plastic is one of the most important technological discoveries of the 20th century.However，it may soon be replaced.The new development—liquid wood—can replace plastics in all branches of modern industries.

Plastic as a material enjoys the biggest demand in the modern world，but it does have a number of drawbacks.First and foremost，plastic isn’t recyclable.Secondly，it contains toxins (毒物) helping develop cancerous diseases.Finally，it’s made of oil and oil reserves aren’t endless.

The? liquid wood technology is likely to replace plastic and provide mankind with new materials for many years ahead.Norbert Eisenfreich，a senior researcher at? the Faunhofer Institute for Chemical Technology (ICT) in Germany，said that arboform，the new material，is made of lignin (木质素)，which can be obtained from soft tissues of wood.Once mixed with several other materials，it turns into solid and non?toxic alternative for plastics.

ICT team leader Emilia Regina Inone?Kauffmann said the wood?working industry separates wood into three basic components，including lignin.Lignin isn’t used for the production of paper.Specialists of ICT mixed lignin with several natural materials and thus invented the material which could be melted and molded (铸型)．

When solid，arboform looks like plastic and possesses the qualities of polished wood.It can be used for the production of any items.Arboform is already used for the production of car parts which require extra strength.In addition，liquid wood can be recycled repeatedly.The material preserved all of its qualities even if it’s reprocessed ten times.

However，the new invention doesn’t enjoy an extensive use due to the high content of sulphur (硫) in it.German researchers are sure to reduce the amount of sulphur by 90 percent very soon to make arboform usable for home needs.

1.According to the passage，plastic________.

A．plays a big role in the modern world

B．helps to protect our environment in some way

C．has been replaced by the newly discovered material

D．helps us to reduce the use of petrol

2.What’s the advantage of arboform over plastics?

A．It is easily made from natural oil.

B．It is more widely used in household.

C．It is recyclable and friendly to the environment.

D．It contains no poisonous materials.

3.It can be concluded that German researchers will focus their future work firstly on________.

A．the material’s extensive use

B．the content of sulphur in arboform

C．the production cost of arboform

D．the qualities of liquid wood

4.The main purpose of the passage is to________.

A．advertise the new material—arboform

B．introduce liquid wood which will replace plastic

C．advertise new products made of arboform

D．show readers how to produce arboform

.Can you imagine your doctor warning that taking a bath could be unhealthy? In the early 1800s, many doctors thought that bathtubs(浴缸) could carry diseases, so they advised against their use. The advice wasn’t based on personal experience, because few of the doctors owned bathtubs. The White House did not even have a bathtub until 1851.
In the 19th century, only one home out of six had a bathroom. A child took only one bath a week. On Saturday nights, children all lined up for their turns to wash in a wooden bathtub in the kitchen. Mothers had to boil the water on the stove and carry it over to fill the bathtub. It’s no wonder that children could not jump into a bathtub as they do today.
When the first bathtubs were introduced, even their makers weren’t sure whether the new fashion would last. They advertised their products as water containers that “could be used as bathing tubs”.
The bathtub became popular in America shortly after World War I. By then most middle-class families had indoor taps. At first most bathtubs were made of wood, but as the popularity of the product increased, so did the creativity of bathtub makers. Before porcelain(瓷) bathtubs there were rubber ones like the plastic swimming pools kids use today. In the past few years owners often invited guests to see them. They told their friends how wonderful baths in these bathtubs could be.
Now doctors no longer warn that bathtubs carry diseases. Instead, they tell their patients about the benefits of frequent bathing in the bathtubs. Maybe one of the best reasons why doctors encourage frequent trips to the bathtub is that bathed patients smell better!
47. Many doctors in the past were against using bathtubs because ______.
A. they didn’t have their own bathtubs
B. they thought bathtubs could carry diseases.
C. the children might hurt themselves in the bathtubs
D. bathtubs were too expensive for the common families
48. Why couldn’t children jump into a tub in the 19th century as they do today?
A. It was unhealthy to do so.      B. The bathtubs were not enough.
C. Mothers were always busy.     D. The bathtubs were made of wood.
49. Which of the following is true according to the text?
A. Some different materials can be used to make bathtubs.
B. In the 19th century only one home out of seven had a bathroom.
C. The bathtub became popular when they were introduced to the market.
D. Children prefer the bathtubs made of plastic to those made of porcelain.
50. It can be inferred from the last paragraph that ______.
A. all the doctors have bathtubs in their homes
B. the doctors have realized the advantages of bathtubs
C. the doctors will make lots of money by advertising bathtubs
D. the patients should take a bath before going to see a doctor

Plastic is one of the most important technological discoveries of the 20th century. However, it may soon be replaced. The new development- liquid wood- can replace plastics in all branches of modern-day industries.

Plastic as a material enjoys the biggest demand in the modern world, but it does have a number of drawbacks. First and foremost, plastic isn’t recyclable. Secondly, it contains toxins (毒物) helping develop cancerous diseases. Finally, it’s made of oil and oil reserves aren’t endless.

The liquid wood technology is likely to replace plastic and providing mankind with new materials for many years ahead. Norbert Eisenfreich, a senior researcher at the Faunhofer Institute for Chemical Technology in Germany (ICT), said that arboform, the new material, is made of lignin(木素质）, which can be obtained from soft tissues of wood. Once mixed with several other matenals, it turns into solid and non-toxic alternative for plastics.

ICT team leader Emilia Regina Inone-Kauffmann said the wood-working industry separates wood into three basic components, including lignin. Lignin isn’t used for the production of paper. Specialists of ICT mixed lignin with several natural materials and thus invented the material which could be melted and molded (铸型）.

When solid, arboform looks like plastic and possesses tho qualitie of polished wood. It can be used for the production of any items. Arboform is already used for the production of car parts which require extra strength. In addition, liquid wood can be recycled repeatedly. The material preserved all of its qualities even if it’s reprocessed ten times.

However, the new invention doesn’t enjoy an extensive use due to the high content of sulfur(硫) in it. German researchers are sure to reduce the amount of sulfur by 90% very soon to make arboform usable for home needs.

71. According to the passage, plastic        .

A. helps us to reduce the use of petrol

B. helps to protect our environment in some way

C. does harm to our society in some way

D. has been replaced by the newly discovered material

72. What’s the advantage of arboform over plastic?

A. It is easier made from natural oil.

B. It is more widely used in household

C. It is recyclable and friendly to environment.

D. It contains no poisonous materials.

73. The underlined word “altemative” in Paragraph 3 means        .

A. lignin or arboform                                B.soft tissues of wood

C. plastics or wood                                    D. mixture of several materials

74. It can be concluded that German researchers will focus their future work firstly on     .

A. the material’s extensive use                    B. the content of sulfur in arboform

C. the production cost of arboform                     D. the qualities of liquid wood

75. The main purpose of the text is to     .

A.introduce liquid wood which will replace plastic

B.show readers how to produce arboform

C.advertise the new material-arboform

D.advertise new products made of arboform