Question

阅读理解 　　“A key chemical of brain development may play a role in explaining why some people are genetically(由基因决定地)likely to suffer from anxiety and could lead to new treatments, ” the US researchers said． 　　They said highly anxious rats which were kept had very low levels of a brain chemical called growth factor FGF2, compared with the rats that were more relaxed．But when they improved the anxious rats’ living conditions－giving them new toys to play with and a bigger cage to live in-levels of this brain chemical increased and they became less anxious． 　　“The levels of this brain chemical increased in response to the experiences that the rats were exposed to．It also decreased their anxiety．” Javier Perez of the University of Michigan said in a telephone interview．“It made them behave the same way as the rats that were relaxed, ” he said． 　　In a former study of people who were severely depressed before they died, the team found the gene that makes FGF2 was producing very low levels of the growth factor, which is known primarily for organizing the brain during development and repairing it after injury． 　　Perez thinks the brain chemical may be a marker for genetic vulnerability(脆弱性)to anxiety and depression．But it can also respond to changes in the environment in a positive way, possibly by preserving new brain cells． 　　Although both the calm and anxious rats produced the same number of new brain cells, these cells were less likely to survive in the high-anxiety rats, the team found．Giving the rats better living conditions or injecting them with FGF2 helped improve cell survival． 　　“This discovery may help find the way for new, more specific treatments for anxiety that will not be based on sedation(药物镇静), but will instead fight the real cause of the disease, ” Dr．Pier Vincenzo Piazza from France said in a statement． (1) We know from the passage that with the levels of FGF2 decreasing, the rats will ________． [　　] A． die of anxiety soon B． suffer from a headache C． become more relaxed D． become more anxious (2) Which of the following is a way to increase the levels of FGF2? [　　] A． Letting the anxious rats live alone． B． Improving the living conditions of the anxious rats． C． Injecting the relaxed rats with sedatives． D． Giving the anxious rats more enemies． (3) What's the main influence of the new discovery? [　　] A． Doctors will cure anxiety without sedation． B． Doctors will find the real cause of anxiety． C． Doctors may find new medicine for anxiety． D． Doctors may treat anxiety with a new special medicine． (4) Which of the following would be the most suitable title for the passage? [　　] A． Anxious rats and relaxed rats B． Anxiety-a serious mental disease C． Scientific research into the brain is important D． Brain chemical may play a key role in anxiety

Answer 1

答案：1．D;2．B;3．A;4．D;
解析：

(1)	考查细节理解。根据第二段最后一句中的“levels of this brain chemical increased and they became less anxious”可知，FGF2的减少会使老鼠变得更加焦虑。
(2)	考查推理判断，根据第二段中的“But when they improved the anxious rats’ living conditions－giving them new toys to play with and a bigger cage to live in”及倒数第二段的最后一句可推知，改善那些感到焦虑的老鼠的居住条件可以增加FGF2。
(3)	考查推理判断。根据最后一段中的“This discovery may help find the way for new, more specific treatments for anxiety that will not be based on sedation(药物镇静), but will instead fight the real cause of the disease”可推知医生不需要用药物镇静就可以治愈焦虑。
(4)	考查标题概括。通读全文可知，本文主要讲述了通过对老鼠进行试验研究人员发现大脑中的一种化学成分对焦虑起着重要的作用。故D项作为本文的标题最合适。