六级练习2013.11.02
[audio]http://sound.yywz123.com/tingbbs/cet6/cet620131102.mp3[/audio]When a particular drug is taken by millions, some people may not respond in a predictable way, even though the drug has been tested.
A patient may also acquire a tolerance for a certain drug, which means the patient has to (1)______________________. Tolerance may lead to habituation, in which the person becomes so dependent on the drug that he or she becomes addicted to it. (2)_________________________when the drug is taken away. Finally, drugs often have unwanted side effects. This usually causes only minor discomfort, (3)____________________. Certain drugs, however, can produce serious adverse reactions.
**** Hidden Message ***** take a ever larger doses to produce the desired effect.
addiction causes severe psychological and physical disturbances
such as skin rush , headache or sleepiness addiction causes severe psychological and physical
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