欧美日韩黄网欧美日韩日B片|二区无码视频网站|欧美AAAA小视频|久久99爱视频播放|日本久久成人免费视频|性交黄色毛片特黄色性交毛片|91久久伊人日韩插穴|国产三级A片电影网站|亚州无码成人激情视频|国产又黄又粗又猛又爽的

Lead deposits, which accumulated in soil and snow during the 1960’s and 70’s, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that the Clean Air Act has mandated unleaded gas use in the United States, the lead accumulation worldwide has decreased significantly.

A study published recently in the journal Nature shows that air-borne leaded gas emissions from the United States were the leading contributor to the high concentration of lead in the snow in Greenland. The new study is a result of the continued research led by Dr. Charles Boutron, an expert on the impact of heavy metals on the environment at the National Center for Scientific Research in France. A study by Dr. Boutron published in 1991 showed that lead levels in arctic snow were declining.

In his new study, Dr. Boutron found the ratios of the different forms of lead in the leaded gasoline used in the United States were different from the ratios of European, Asian and Canadian gasolines and thus enabled scientists to differentiate (區(qū)分) the lead sources. The dominant lead ratio found in Greenland snow matched that found in gasoline from the United States.

In a study published in the journal Ambio, scientists found that lead levels in soil in the Northeastern United States had decreased markedly since the introduction of unleaded gasoline.

Many scientists had believed that the lead would stay in soil and snow for a longer period.

The authors of the Ambio study examined samples of the upper layers of soil taken from the same sites of 30 forest floors in New England, New York and Pennsylvania in 1980 and in 1990. The forest environment processed and redistributed the lead faster than the scientists had expected.

Scientists say both studies demonstrate that certain parts of the ecosystem respond rapidly to reductions in atmospheric pollution, but that these findings should not be used as a license to pollute.

57.　 The study published in the journal Nature indicates that ________.

A.　 the Clean Air Act has not produced the desired results

B.　 lead deposits in arctic snow are on the increase

C.　 lead will stay in soil and snow longer than expected

D.　 the US is the major source of lead pollution in arctic snow

58.　 Lead accumulation worldwide decreased significantly after the use of unleaded gas in the US　 _____ .

A.　 was discouraged B.　 was enforced by law

C.　 was prohibited by law　　　　　 D.　 was introduced

59.　 How did scientists discover the source of lead pollution in Greenland?

A.　 By analyzing the data published in journals like Nature and Ambio.

B.　 By observing the lead accumulations in different parts of the arctic area..

C.　 By studying the chemical elements of soil and snow in Northeastern America.

D.　 By comparing the chemical compositions of leaded gasoline used in various countries.

60.　 The authors of the Ambio study have found that ________.

A.　 forests get rid of lead pollution faster than expected

B.　 lead accumulations in forests are more difficult to deal with

C.　 lead deposits are widely distributed in the forests of the US

D.　 the upper layers of soil in forests are easily polluted by lead emissions

A new plan for getting children to and from school is being started by a local government in Eastern England. This could end the worries of many parents fearful for their children’s safety on the roads.

Until now the local government has only been prepared to provide bus services for children living more than three miles from their school, or sometimes less if special reasons existed. Now it has been decided that if a group of parents ask for help in organizing transport they will be prepared to go ahead, as long as the arrangement will not lose money and children taking part will be attending their nearest school.

The new plan is to be fired out this term for children living at Milton who attend Impington School. The children live just within the three-mile limit and the local government said in the past that they would not undertake to provide free transport to the school. But now they have agreed to offer a sum of money for a bus service from Milton to Impington and back, a plan which has the support of the school’s headmaster. Between 50 and 60 parents have said they would like their children to take part. Final calculations have still to be carried out, but a government official has said the cost to parents should be less than ￡20 a term. They have been able to arrange the service at a low cost because there is already an agreement with the bus company for a bus to take children who live further away to Impington. The same bus would now just make one more journey to pick up the Milton children. The official said they would get in touch with other groups of parents who in the past had asked if transport could be provided for their children, to see if they would like to take part in the new plan.

1. What is the aim of the plan?

A.　 To prevent the students’ road accidents　 B.To relieve the traffic pressure

C.　 To save time for the parents and students　 D.To help the parents save money

2. How can the local government arrange the new bus service at a low cost?

A.　 By letting the bus run in the morning only

B.　 By limiting the number of the students

C.　 By getting the support from the headmaster

D.　 By linking the new bus service with the existing one

3. Which of the following is possible if the plan is carried out?

A.　 The bus company will make much more money

B.　 The children can choose whatever school they like

C.　 The parents can get rid of their worries

D.　 The students in Impington School can have free bus rides

4 This passage is most probably _____

A.　 a personal letter B. an advertisement C. a headmaster’s report D. a newspaper article

根據短文內容，從短文后的選項中選出能填入空白處的最佳選項。選項中有一項為多余選項。

A.　Goods for auction (拍賣) sales

　　B.　Definition of bidding

　　C.　Way to sell more goods by auction

　　D.　Auction sales in history

　　E.　Brief introduction to auctions

　　F.　Making a larger profit as an auctioneer

1.______

Auctions are public sales of goods, conducted by an officially approved auctioneer. He asks the crowd assembled in the auction-room to make offers, or “bids”, for the various items on sale. He encourages buyers to bid higher figures, and finally names the highest bidder as the buyer of the goods. This is called “knocking down” the goods, for the bidding ends when the auctioneer strikes a small hammer on a table at which he stands.

2. ______

The ancient Roman probably invented sales by auction, and the English word comes from the Latin auction, meaning “increasing”. The Romans usually sold in this way the goods taken in war. In England in the eighteenth centuries, goods were often sold “by the candle”: a short candle was lit by the auctioneer, and bids could be made while it stayed alight.

3. ______

Practically all goods whose qualities vary are sold by auction. Among these are coffee, skins, wool, tea, furs, silk and wines. Auction sales are also usual for land and property, furniture, pictures, rare books, old china and similar works of art.

4. ______

An auction is usually advertised beforehand with full particulars of the articles to be sold and where and when they can be viewed by potential buyers. If the advertisement cannot give full details, catalogues are printed, and each group of goods to be sold together, called a “l(fā)ot”, is usually given a number. The auctioneer need not begin with Lot 1 and continue in the order of numbers: he may wait until he notices the fact that certain buyers are in the room and then produce the lots they are likely to be interested in.

5. ______

The auctioneer’s services are paid for in the form of a percentage of the price the goods are sold for. The auctioneer therefore has a direct interest in pushing up the bidding as high as possible. He will not waste time by starting the bidding too low. He will also play on the opponents among his buyers and succeed in getting a high price by encouraging two business competitors to bid against each other.

根據短文內容，從短文后的選項中選出能填入空白處的最佳選項。選項中有一項為多余選項。
A.　Goods for auction (拍賣) sales
　　B.　Definition of bidding
　　C.　Way to sell more goods by auction
　　D.　Auction sales in history
　　E.　Brief introduction to auctions
　　F.　Making a larger profit as an auctioneer
【小題1】______
Auctions are public sales of goods, conducted by an officially approved auctioneer. He asks the crowd assembled in the auction-room to make offers, or “bids”, for the various items on sale. He encourages buyers to bid higher figures, and finally names the highest bidder as the buyer of the goods. This is called “knocking down” the goods, for the bidding ends when the auctioneer strikes a small hammer on a table at which he stands.
【小題2】 ______
The ancient Roman probably invented sales by auction, and the English word comes from the Latin auction, meaning “increasing”. The Romans usually sold in this way the goods taken in war. In England in the eighteenth centuries, goods were often sold “by the candle”: a short candle was lit by the auctioneer, and bids could be made while it stayed alight.
【小題3】 ______
Practically all goods whose qualities vary are sold by auction. Among these are coffee, skins, wool, tea, furs, silk and wines. Auction sales are also usual for land and property, furniture, pictures, rare books, old china and similar works of art.
【小題4】 ______
An auction is usually advertised beforehand with full particulars of the articles to be sold and where and when they can be viewed by potential buyers. If the advertisement cannot give full details, catalogues are printed, and each group of goods to be sold together, called a “l(fā)ot”, is usually given a number. The auctioneer need not begin with Lot 1 and continue in the order of numbers: he may wait until he notices the fact that certain buyers are in the room and then produce the lots they are likely to be interested in.
【小題5】 ______
The auctioneer’s services are paid for in the form of a percentage of the price the goods are sold for. The auctioneer therefore has a direct interest in pushing up the bidding as high as possible. He will not waste time by starting the bidding too low. He will also play on the opponents among his buyers and succeed in getting a high price by encouraging two business competitors to bid against each other.