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  3. Multidisciplinary science is all the rage these days. Even (31), the overlap between archaeology and pharmacology is not, at fir

Multidisciplinary science is all the rage these days. Even (31), the overlap between archaeology and pharmacology is not, at fir

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问题     Multidisciplinary science is all the rage these days. Even (31), the overlap between archaeology and pharmacology is not, at first (32), obvious. But there is a connection. An analytical technique developed for the (33), used to work out how old things are, is now (34) used in the latter, to see if promising drugs are likely to fail (35) expensive clinical trials are undertaken.
    At the (36), a third of drug candidates do not pass such trials. This may be (37) they fail to reach the part of the body where they are (38) to work—many molecules, for (39), cannot cross from the bloodstream into the brain. Or it may be that the body breaks down the active ingredients before the drug has time to act. Identifying (40) problems early in the testing process would be a boon. Trials on (41) can help, but how other species react is not always a good indication of how people will. What is needed is a way of testing potential drugs on people, (42) in a way that cannot possibly cause any harm. That is (43) the archaeologists come in.
    (44) decades, archaeologists have used a technique called carbon dating to work (45) how old their finds are. Some of the carbon dioxide absorbed by plants during photosynthesis is (46). That is because it contains carbon atoms which are (47) than run-of-the-mill carbon, and are unstable. The radioactive carbon atoms weigh 14 atomic units, (48) nm-of-the-mill ones weigh 12 units. Food grains, scraps of cloth and so on can thus be dated by finding out how (49) radioactive carbon is left in them: the less there is, the (50) they are. (278 words)

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答案radioactive
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