编辑点评： GRE阅读考试的材料，非常强调逻辑的关系，所以逻辑要点是大家在解GRE阅读题的时候的关键，本文就为大家例举了这样一篇逻辑短文，供大家参考和练习。 随着GRE阅读考试的难度日益增加，大家需要有针对性地进行练习，本文为大家例举的就是逻辑短文的练习，文末还附有答案，供大家更好地练习。 Until about five years ago, the very idea that peptide hormones might be made anywhere in the brain besides the hypothalamus was astounding
But laboratory after laboratory found that antiserums to peptide hormones, 5 when injected into the brain, bind in places other than the hypothalamus, indicating that either the hormones or substances that cross-react with the antiserums are present
The immunological method of detecting peptide hormones by means of antiserums, however, is 10 imprecise
Cross-reactions are possible and this method cannot determine whether the substances detected by the antiserums really are the hormones, or merely close relatives
Furthermore, this method cannot be used to determine the location in the body where the detected 15 substances are actually produced
New techniques of molecular biology, however, provide a way to answer these questions
It is possible to make specific complementary DNA s that can serve as molecular probes to seek out the messenger RNA s 20 of the peptide hormones
The brain cells containing these mRNA s can then be isolated and their mRNA s decoded to determine just what their protein products are and how closely the products resemble the true peptide hormones
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Which of the following titles best summarizes the passage? Is Molecular Biology the Key to Understanding Intercellular Communication in the Brain? Molecular Biology: Can Researchers Exploit Its Techniques to Synthesize Peptide Hormones? The Advantages and Disadvantages of the Immunological Approach to Detecting Peptide Hormones Peptide Hormones: How Scientists Are Attempting to Solve Problems of Their Detection Peptide Hormones: The Role Played by Messenger RNA s in Their Detection 12
The passage suggests that a substance detected in the brain by use of antiserums to peptide hormones may have been stored in the brain for a long period of time play no role in the functioning of the brain have been produced in some part of the body other than the brain have escaped detection by molecular methods play an important role in the functioning of the hypothalamus 13
Which of the following is mentioned in the passage as a drawback of the immunological method of detecting peptide hormones? It cannot be used to detect the presence of growth regulators in the brain
It cannot distinguish between the peptide hormones and substances that are very similar to them
It uses antiserums that are unable to cross the blood-brain barrier
It involves a purification process that requires extensive training in endocrinology
It involves injecting foreign substances directly into the bloodstream
答案：D/C/B 上文的题目大家答对了几题?大家不仅要多做题，更要善于总结，这样才会有针对性地提高。
