大悲剧啊，那几个传说中的高频一个没碰到。 填空到是遇到了那个impassion那个。 同志们要看好这个题目哈。 1 我遇到的是Although B is not impasssion ， he is anything but ---- 这个是apathy 不是zealist。 although 前后反，not impassive 不热情，后面就是热情=anything but 冷漠啦。大家考试看仔细 although那半句有没有not哈我的肯定有啦
The old wood effect or old wood problem is a pitfall encountered in the archaeological technique of Carbon 14 dating. A sample will provide misleading or confusing results if materials of different ages are deposited in the same context. Stratification is not always clear cut in practice. In the case of dating megalithic tombs, indirect evidence for the age of the tomb must always be obtained, because stone (or the time of moving a stone) can not be dated. When a number of objects are recovered from one deposit, the terminus post quem is based on the dating from the 'youngest' find. Even though other items in the same stratum indicate earlier dates, they may have been deposited at the same time. The deposit must be as young, or younger than the youngest object it contains. Thus excavators look to post holes, pits, or find spots under the orthostats for clues to construction dates. The possibility that something (organic) was already in situ must always be considered, especially if the results appear suspiciously early. The old wood problem can appear in marine archaeology. Researchers need to check if stumps from a Mesolithic or Palaeolithicsubmerged forest are to be found in the area (If they do, the possibility of one sticking up through - for example - a shipwreck and giving misleading dates must be considered). When radiocarbon ages are combined - especially in instances where samples do not come from the same part of one organism - problems can arise. If compelling archaeological reasons for supposing that the ages come from exactly contemporary samples do not exist then results must be regarded as suspect. [1] If there exists no prior reason to believe that two samples are truly of the same age and even if their ages are statistically indistinguishable, they are as likely to be as far apart in true age as the measured difference between them as they are to be of the same age. [2] Charcoal turns out, for many reasons, to be an ideal medium for carbon dating. When long-lived tree species such as oak and juniper, are used, however, there is a particular danger of encountering the 'old wood' problem. For example; the date you are measuring may be from heartwood already many centuries old by the time the tree was cut down. Another difficulty is that of possible time-lags between felling and final deposition. The timber may have had an extensive history of use and re-use. An ideal material to date, if available, would be twigs of such trees as hazel. And of course, the old adage of 'one date is no date' always applies. A representative spread of dates is required before interpretation can be attempted. [3]
我遇到的：考古估计年龄用 old wood 方法，判断年代，说这个方法好像比其他什么方法靠谱。然后出现个句子，估计开始说缺点了，但这个句子我没太读懂，是说 old wood 方法render a merely max-estamited time 坑爹的是我把render 和mere 意思忘记了。。。哎只背3000的娃伤不起啊，回去背六记单词吧。 然后我想了好久，一共两个问题感觉都是围绕这里出的。 我就不知道到底是高估了呢还是低估了呢。 文章后面又举例子说该方法不准确，humid 地方木头腐蚀快，另一种什么情况又腐蚀慢还是什么的。
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发表于 2012-9-15 23:44:27
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