【托福备考】托福听力背景材料——考古年代的测定
- 2015年09月22日12:00 来源：小站整理
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美国有很多的大城市，基本上每个城市都有自己的别名。这些别名大都与该城市的历史、地理、社会习俗等因素有关。这些美国的城市名及别名如果出现在托福听力中，大家就可以联想到相关的文化背景，节省托福听力时间。这样有特色的美国州名和相应的别名是非常好的托福听力背景材料，大家不需要一定要记住这些别称的意思，但是能够做到在听到名称的时候反应出是哪个地方就可以帮我们很大的忙了。
Dating Methods in Archaeology
If there is one fundamental issue on which most archaeologists can generally agree, it is the importance of chronology in studying the past. Although one of the most important contributions that archaeology can make is the study of cultures over long time spans, control of the time dimension is crucial in almost all kinds of archaeological research. In studying the archaeological record, the archaeologist needs to differentiate those materials that are contemporary and those that reflect the passage of time. Given the importance of establishing the temporal relationships of archaeological remains, it is not surprising that until the introduction of dating techniques from the physical sciences (e.g., chemistry and nuclear physics), issues of chronology dominated archaeology. Archaeologists can now access a wide variety of techniques to estimate the age of archaeological remains, and can now turn their attention to issues other than chronology.
The dating methods used by archaeologists vary considerably in precision and the nature of the material actually dated. Age determinations for archaeological materials may be direct or indirect. Direct dates are derived from the actual artifact, feature or ecofact to determine the age of the material. Indirect dates are based on material associated with the archaeological item of interest. For example, ash in an ancient hearth can be dated by the radiocarbon dating method (discussed below) and other material, such as pottery, stone tools, and fragments of animal bone associated with the hearth, can then be indirectly assigned the same age. This assignment, however, assumes that there is sufficient evidence indicating that both the hearth and the artifacts reflect the same contemporaneous event, thus allowing the extension of the direct date to the other related material.
