Radiometric dating continues to be the predominant way scientists date geologic timescales. Techniques for radioactive dating have been tested and fine-tuned for the past 50+ years. Forty or so different dating techniques have been utilized to date, working on a wide variety of materials. Dates for the same sample using these different techniques are in very close agreement on the age of the material.
Possible contamination problems do exist, but they have been studied and dealt with by careful investigation, leading to sample preparation procedures being minimized to limit the chance of contamination. Hundreds to thousands of measurements are done daily with excellent precision and accurate results. Even so, research continues to refine and improve radiometric dating to this day
Source:http://en.wikipedia.org/wiki/Age_of_the_Earth
第二篇： GERMAN RAILWAY
第二篇讲的是近代德国基于铁路工业的发展。
这篇结构为很简洁的三段。第一段总起说了下德国发展铁路后带动了一系列的发展进步。第二段细说了下铁路引领了什么进步，主要是铁、煤以及其他诸如化工产业之类的发展。然后作者列举了一个现象，通过铁路带动化工产业这个例子来阐述。(这里考作者的阐述方法)之后还强调了下铁路带动了一个P城市的兴旺，这个城市通过兴建各种配套设施啥的，体现了铁路给城市带来的翻天覆地的变化。第三段主要还是围绕P展开说了下，说由于铁路使得市场扩大了之类的。之后说了铁路还帮助人们能够在更大范围找工作以及周边产业给了更多的人就业机会。(这里有双选题)最后还说铁路打通了德国东西的连接，(运河是南北的)标志着德国工业的振兴blabla。
German Railways.
As far as railway development is concerned, no corner of the world is making more rapid progress than Germany. A recent survey issued by the German railway authorities states that, during 1927, the German railways handled 1,909,000,000 passengers and 489,000,000 tons of merchandise. Steam locomotives number 24,575 and electric locomotives 316. The German railways operate some 62,940 passenger carriages, and the stock of goods wagons totals 674,318. As a result of a consistent effort at standardization, the number of types of locomotives in service on the German lines has been reduced from 250 in 1920 to 40 at the present time. Despite this standardization, the door is being left open to experiment, and, at the moment, attention is being devoted to the development of high pressure locomotives, some of these experimental machines having steam pressures as high as 880lbs. per square inch.
German Railway history began with the opening of the steam-hauled Bavarian Ludwig Railway between Nuremberg and Fürth on 7 December 1835. This had been preceded by the opening of the horse-hauled Prince William Railway on 20 September 1831. The first long distance railway was the Leipzig-Dresden railway, completed on 7 April 1839.
German unification in 1871 stimulated consolidation, nationalization into state-owned companies, and further rapid growth. Unlike the situation in France, the goal was support of industrialization, and so heavy lines crisscrossed the Ruhr and other industrial districts, and provided good connections to the major ports of Hamburg and Bremen. By 1880, Germany had 9,400 locomotives pulling 43,000 passengers and 30,000 tons of freight, and forged ahead of France
Social and economic benefits
【P的兴旺】Prussia nationalized its railways in an effort both to lower rates on freight service and to equalize those rates among shippers. Instead of lowering rates as far as possible, the government ran the railways as a profitmaking endeavor, and the railway profits became a major source of revenue for the state. The nationalization of the railways slowed the economic development of Prussia because the state favoured the relatively backward agricultural areas in its railway building. Moreover, the railway surpluses substituted for the development of an adequate tax system.
In order to enable the free exchange of goods wagons between the different state railway administrations, the German State Railway Wagon Association (DeutscherStaatsbahnwagenverband or DSV) was formed in 1909. The standard wagons that resulted are often referred to as 'DSV wagons'.
The standardisation of goods wagons under the German State Railway Wagon Association, that had produced the Verbandsbauart ('Association design') wagons, continued as new designs using interchangeable components were introduced from about 1927. These were the Austauschbauart ('interchangeable design') wagons. The 1930s saw the introduction of welded construction and solid wheels replacing spoked wheels on new goods wagons. As the Second World War loomed, production was geared towards the war effort. The focus was on fewer types but greater numbers of so-called Kriegsbauart or wartime designs for the transportation of large quantities of tanks, vehicles, troops and supplies.
【德国铁路对工业影响】During the Second World War, austere versions of the standard locomotives were produced to speed up construction times and minimise the use of imported materials. These were the so-called war locomotives (Kriegslokomotiven and ?bergangskriegslokomotiven)。 Absent a good highway network and trucks, the Germans relied heavily on the railways, supplemented by slower river and canal transport for bulk goods. The rail yards were the main targets of the "transportation strategy" of the British and American strategic bombing campaign of 1944-45, and resulted in massive destruction of the system.
【东德和西德的铁路】After World War II, Germany (and the DRG) was divided into 4 zones: US, British, French and Soviet. The first three eventually combined to form the Federal Republic of Germany (the West) and the Russian zone became the German Democratic Republic (the East)。 German territories beyond the Oder were ceded to Poland except for the northern part of East Prussia, which was ceded to the Soviet union in 1945.From 1949, the new governments assumed authority for railway operations. The DRG's (or DR's) successors were named Deutsche Bundesbahn (DB, German Federal Railways) in West Germany, and Deutsche Reichsbahn (DR, German State Railways) in East Germany kept the old name to hold tracking rights in western Berlin.
