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【简答题】

The Pacific island nation of Nauru used to be a beautiful place. Now it is an ecological(生态的) disaster area. Nauru’s heartbreaking story could have one good consequence — other countries might learn from its mistakes. For thousands of years, Polynesian people lived the remote island of Nauru, far from western civilization. The first European to arrive was John Fearn in 1798. He was the British captain of the Hunter, a whaling ship. He called the island Pleasant Island. However, because it was very remote, Nauru had little communication with Europeans at first. The whaling ships and other traders began to visit, bringing guns and alcohol. These elements destroyed the social balance of the twelve family groups on the island. A ten-year civil war started, which reduced the population from 1,400 to 900. Nauru’s real troubles began in 1899 when a British mining company discovered phosphate (磷酸盐)on the island. In fact, it found that the island of Nauru was nearly all phosphate, which a very important fertilizer for farming. The company began mining the phosphate. A phosphate mine is not a hole in the ground; it is a strip mine(带状矿). When a company strip-mines, it removes the top layer(层) of soil. Then it takes away the material it wants. Strip mining totally destroys the land. Gradually, the lovely island of Nauru started to look like the moon. In 1968, Nauru became one of the richest countries in the world. Every year the government received millions and millions of dollars for its phosphate. Unfortunately, the leaders invested the money unwisely and lost millions of dollars. In addition, they used millions more dollars for personal expenses. Soon people realized that they had a terrible problem — their phosphate was running out. Ninety percent of their island was destroyed and they had nothing. By 2000, Nauru was financially ruined. Experts say that it would take approximately $433,600,000 and more than 20 years to repair the island. This will probably never happen. 小题1:What might be the author’s purpose in writing the text? A.To seek help for Nauru’s problems. B.To give a warning to other countries. C.To show the importance of money. D.To tell a heartbreaking story of a war. 小题2:What was Nauru like before the Europeans came? A.Rich and powerful. B.Modern and open. C.Peaceful and attractive. D.Greedy and aggressive. 小题3:The ecological disaster in Nauru resulted from . A.soil pollution B.phosphate over mining C.farming activity D.whale hunting 小题4:Which of the following was a cause of Nauru’s financial problem? A.Its leaders misused the money. B.It spent too much repairing the island. C.Its phosphate mining cost much money. D.It lost millions of dollars in the civil war. 小题5:What can we learn about Nauru from the last paragraph? A.The phosphate mines were destroyed. B.The leaders will take the experts’ words seriously. C.The island was abandoned by the Nauruans. D.The ecological damage is difficult to repair.

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题目标签:磷酸盐带状
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【单选题】Organic FoodOrganic farming was among the fastest growing segments of U.S. agriculture during the 1990s. The value of retail. sales of organic food was estimated to be $16 billion in 2004. According t...

A.
As you can imagine, organic agricultural practices are quite distinct from those of "conventional" fanning.
B.
Organic farmers:
C.
feed soil and build soil matter with natural fertilizer to grow their crops use insect predators, mating disruption, traps and barriers to protect crops from pests and disease make use of crop rotation, mechanical tillage and hand-weeding, as well as cover crops, mulches, flame weeding and other management methods to control weed growth.As a last resort, organic farmers may apply certain botanical or other non-synthetic pesticides. Conventional farmers:,
D.
apply chemical fertilizers to the soil to grow their crops spray with insecticides to protect crops from pests and disease use synthetic herbicides to control weed growth.
E.
How Do I Know if a Food is Organic
F.
Look for the word "organic" on vegetables or pieces of fruit, or on the sign above the organic produce display. The word "organic" may also appear on packages of meat, cartons of milk or eggs, cheese and other single-ingredient foods. Foods labeled "100 percent organic" must contain only organic ingredients. Products containing at least 70 percent organic content can be labeled "made with organic ingredients". Those foods labeled simply "organic" must have at least 95 percent organic ingredients, by weight or fluid volume, excluding water and salt. Anyone who knowingly sells or labels a product "organic" that is not produced and handled in accordance with these regulations can face a civil penalty of up to $10,000.
G.
Foods grown and processed according to the federal standards will in most cases bear the seal "USDA Organic". As its use is voluntary, companies may choose not to display the seal.
H.
Why Should I Care if a Food is Organic According to the USDA, organic food production allows farmers to lower input costs, decrease reliance on nonrenewable resources, capture high-value markets and premium prices, and boost farm income. Organic agriculture also has many important environmental, benefits:
I.
It promotes sustainability by establishing an ecological balance to prevent soil fertility or pest problems. In the long run, organic farms tend to conserve energy and protect the environment by maintaining ecological harmony.
J.
It enhances biodiversity, or the presence of multiple plant and animal species. Having a highly diverse genetic pool becomes useful in the future when beneficial characteristics can be tapped.
.
Because organic agriculture utilizes practices such as crop rotations, inter-cropping, symbiotic associations, cover crops and minimum tillage, the length of time that the soil is exposed to erosive forces is decreased, which minimizes nutrient losses and boosts soil productivity. By not using synthetic fertilizers and pesticides, organic agriculture-reduces pollution of groundwater.
K.
Organic agriculture helps to minimize the greenhouse effect and global warming through its ability to keep carbon in the soil.
L.
Why is Organic Food So Expensive
M.
Prices tend to be higher for organic titan conventional products. As stated on the Web site of the Food and Agriculture Organization (FAO) of the United Nations (UN), certified organic products are generally, more expensive than their conventional counterparts because:
N.
The organic food supply is limited as compared to demand. Production costs for organic foods are typically higher because of greater labor input and because farmers don’t produce enough of a single product to lower the overall cost.
.
Post-harvest handling of relatively small quantities of organic foods results in higher costs because organic and conventional 0roduce must be separated for processing and transportation.
.
Marketing and the distribution chain for organic products are relatively inefficient, and costs are higher because of relatively small volumes.
.
The FAO also notes that as the demand for organic food and products increases, technological innovations and economies of scale should reduce costs of production, processing, distribution and marketing for organic produce.
.
Is Organic Food Better than Conventional Food
.
Organic and conventional food must meet the same quality and safety standards. Organic food differs from conventionally produced food simply in the way it is grown, handled, and processed. There is no scientific evidence to suggest that it is more nutritious or safer than conventional food. A recently published report indicates that organic food is less likely to contain pesticide residues than conventional food. Yet, according to the National Research Council, the traces of pesticides left on conventionally grown products are unlikely to cause an increased cancer risk. Also, if fruits and vegetables are properly washed, most of the chemicals can be removed. As for taste, that’s up to you to decide what you like best. In general, people tend to find that the fresher a food is, the better it tastes, regardless of how it was produced.

【单选题】磷酸盐包埋材料属于

A.
低熔合金铸造包埋材料
B.
中熔合金铸造包埋材料
C.
高熔合金铸造包埋材料
D.
铸钛包埋材料 E.以上均不是

【填空题】带状牺牲阳极具有 ( )的特点。

A.
均匀的电流分布
B.
均匀的电压分布
C.
电压效率高
D.
电流效率高