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仙剑, 还是请教阅读了,刚才做了OG上的文章，并且分析，按照帖子中的画了草图。发现我边读边做笔记的话只能控制在10行左右，不过做题到是命中率高了些。现在找到了一个点，我要是刻意提速的话，（我尝试过便笔记边读每分钟12行）一下子错误率就上来了，并且有些题的时间就加长了，因为重要信息被我忽略了，没法找只好重新来，脑子里知道见过这个词，但是想不起来在哪了。（这里有个GMAT计时器所以我知道我自己的速度）。平衡点找到了。。下面只能从硬功夫往上提了阿。。。 我挑了og11中的文章1，2篇写了小草图，能否请mimi上来时候瞄一下？谢谢！另外考虑mimi文章不在手头边我也贴一下吧。。。不厚道的占了很多篇幅，莫怪阿。、 Caffeine, the stimulant in coffee, has been called “the most widely used psychoactive substance on Earth .” Synder, Daly and Bruns have recently proposed that caffeine affects behavior by countering the activity in (5) the human brain of a naturally occurring chemical called adenosine. Adenosine normally depresses neuron firing in many areas of the brain. It apparently does this by inhibiting the release of neurotransmitters, chemicals that carry nerve impulses from one neuron to the next. (10) Like many other agents that affect neuron firing, adenosine must first bind to specific receptors on neuronal membranes. There are at least two classes of these receptors, which have been designated A1 and A2. Snyder et al propose that caffeine, which is struc- (15) turally similar to adenosine, is able to bind to both types of receptors, which prevents adenosine from attaching there and allows the neurons to fire more readily than they otherwise would. For many years, caffeine’s effects have been attri- (20) buted to its inhibition of the production of phosphodi- esterase, an enzyme that breaks down the chemical called cyclic AMP.A number of neurotransmitters exert their effects by first increasing cyclic AMP concentra- tions in target neurons. Therefore, prolonged periods at (25) the elevated concentrations, as might be brought about by a phosphodiesterase inhibitor, could lead to a greater amount of neuron firing and, consequently, to behav- ioral stimulation. But Snyder et al point out that the caffeine concentrations needed to inhibit the production (30) of phosphodiesterase in the brain are much higher than those that produce stimulation. Moreover, other com- pounds that block phosphodiesterase’s activity are not stimulants. To buttress their case that caffeine acts instead by pre- (35) venting adenosine binding, Snyder et al compared the stimulatory effects of a series of caffeine derivatives with their ability to dislodge adenosine from its receptors in the brains of mice. “In general,” they reported, “the ability of the compounds to compete at the receptors (40) correlates with their ability to stimulate locomotion in the mouse; i.e., the higher their capacity to bind at the receptors, the higher their ability to stimulate locomo- tion.” Theophylline, a close structural relative of caffeine and the major stimulant in tea, was one of the most (45) effective compounds in both regards. There were some apparent exceptions to the general correlation observed between adenosine-receptor binding and stimulation. One of these was a compound called 3-isobuty1-1-methylxanthine(IBMX), which bound very (50) well but actually depressed mouse locomotion. Snyder et al suggest that this is not a major stumbling block to their hypothesis. The problem is that the compound has mixed effects in the brain, a not unusual occurrence with psychoactive drugs. Even caffeine, which is generally (55) known only for its stimulatory effects, displays this property, depressing mouse locomotion at very low concentrations and stimulating it at higher ones. P1 咖啡因和腺嘌呤抢receptor题 结论说明型
Explanation of Conclusion 1. Conclusion : ADenosine→stop release of NT→depress neuron firing Caffeine→bind on A1A2→stop AD to do so→increase neuron firing 2. Why not Old explanation: Caffeine→stop Phosphodi-Esterase→increase AMP→More NT (PE (Enzyme)break down AMP→more AMP(together with)More NT)
SN –Old(习惯笔记时候用-号来代表against): 1. Need too much Caffeine ; 2. Other 化合物说明No PE不等于stimulates 3. Support Conclusion 1 SN:More capability(compete at the receptors)→more ability to stimulate 4. Support Conclusion by providing an explanation of an exception: different level of concentration →
Apparent exception, IBMX
Passage 2Archaeology as a profession faces two major prob- lems. First, it is the poorest of the poor. Only paltry sums are available for excavating and even less is avail- able for publishing the results and preserving the sites (5) once excavated. Yet archaeologists deal with priceless objects every day. Second, there is the problem of illegal excavation, resulting in museum-quality pieces being sold to the highest bidder. I would like to make an outrageous suggestion that (10) would at one stroke provide funds for archaeology and reduce the amount of illegal digging. I would propose that scientific archeological expeditions and govern- mental authorities sell excavated artifacts on the open market. Such sales would provide substantial funds for (15) the excavation and preservation of archaeological sites and the publication of results. At the same time, they would break the illegal excavator’s grip on the market, thereby decreasing the inducement to engage in illegal activities. (20) You might object that professionals excavate to acquire knowledge, not money. Moreover, ancient arti- facts are part of our global cultural heritage, which should be available for all to appreciate, not sold to the highest bidder. I agree. Sell nothing that has unique (25) artistic merit or scientific value. But, you might reply, everything that comes our of the ground has scientific value. Here we part company. Theoretically, you may be correct in claiming that every artifact has potential scien- tific value. Practically, you are wrong. (30) I refer to the thousands of pottery vessels and ancient lamps that are essentially duplicates of one another. In one small excavation in Cyprus, archaeologists recently uncovered 2,000 virtually indistinguishable small jugs in a single courtyard, Even precious royal seal impressions (35) known as/melekh handles have been found in abun- dance---more than 4,000 examples so far. The basements of museums are simply not large enough to store the artifacts that are likely to be discov- ered in the future. There is not enough money even to (40) catalogue the finds; as a result, they cannot be found again and become as inaccessible as if they had never been discovered. Indeed, with the help of a computer, sold artifacts could be more accessible than are the pieces stored in bulging museum basements. Prior to (45) sale, each could be photographed and the list of the purchasers could be maintained on the computer A purchaser could even be required to agree to return the piece if it should become needed for scientific purposes. It would be unrealistic to suggest that illegal digging (50) would stop if artifacts were sold on the open market. But the demand for the clandestine product would be substantially reduced. Who would want an unmarked pot when another was available whose provenance was known, and that was dated stratigraphically by the professional archaeologist who excavated it?
Archaeology as a profession faces two major prob- lems. First, it is the poorest of the poor. Only paltry sums are available for excavating and even less is avail- able for publishing the results and preserving the sites (5) once excavated. Yet archaeologists deal with priceless objects every day. Second, there is the problem of illegal excavation, resulting in museum-quality pieces being sold to the highest bidder. I would like to make an outrageous suggestion that (10) would at one stroke provide funds for archaeology and reduce the amount of illegal digging. I would propose that scientific archeological expeditions and govern- mental authorities sell excavated artifacts on the open market. Such sales would provide substantial funds for (15) the excavation and preservation of archaeological sites and the publication of results. At the same time, they would break the illegal excavator’s grip on the market, thereby decreasing the inducement to engage in illegal activities. (20) You might object that professionals excavate to acquire knowledge, not money. Moreover, ancient arti- facts are part of our global cultural heritage, which should be available for all to appreciate, not sold to the highest bidder. I agree. Sell nothing that has unique (25) artistic merit or scientific value. But, you might reply, everything that comes our of the ground has scientific value. Here we part company. Theoretically, you may be correct in claiming that every artifact has potential scien- tific value. Practically, you are wrong. (30) I refer to the thousands of pottery vessels and ancient lamps that are essentially duplicates of one another. In one small excavation in Cyprus, archaeologists recently uncovered 2,000 virtually indistinguishable small jugs in a single courtyard, Even precious royal seal impressions (35) known as/melekh handles have been found in abun- dance---more than 4,000 examples so far. The basements of museums are simply not large enough to store the artifacts that are likely to be discov- ered in the future. There is not enough money even to (40) catalogue the finds; as a result, they cannot be found again and become as inaccessible as if they had never been discovered. Indeed, with the help of a computer, sold artifacts could be more accessible than are the pieces stored in bulging museum basements. Prior to (45) sale, each could be photographed and the list of the purchasers could be maintained on the computer A purchaser could even be required to agree to return the piece if it should become needed for scientific purposes. It would be unrealistic to suggest that illegal digging (50) would stop if artifacts were sold on the open market. But the demand for the clandestine product would be substantially reduced. Who would want an unmarked pot when another was available whose provenance was known, and that was dated stratigraphically by the professional archaeologist who excavated it?
Passage 2:55lines 考古卖文物题 Problem solving 问题解决型 Para 1 Problems of Archaeology a. poor ; b. illegal ex
Para2 Solution to the problems: sell excavated artifacts
Para 3 Objections and author’s defenders. Objections1: a. knowledge not money; b,available fore all not for the rich; Defend1: sell nothing with unique value O1 to the D1: all Arti are with value D2 to O1: No→Para 4 Para 4: Support his solution (D2 to O1): duplicates a. No place no money in museum. b. Inaccessible in museum but accessible with PC c. Illegal digging not stop but Official sale harm clandestine(秘密暗中私下) | 
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