我有一个贴介绍过自己的背景，其实感觉基础没有问题，因为长期在美帝工作，男盆友又是native speaker，我做题基本没有不认识的词，长难句也不是问题。看Manhattan的语法书什么的都是英文反而比较看的懂。但考完第二次以后砸了两万块上ZB的一对一结果考出600分也是让我质疑了人生很久（人生做的最蠢的决定没有之一）。
消沉加freak out了很久之后，现在又振作起来要考第四次了。这期间还换了次工作。
四月20号考试。
在学习的过程中会有些思考和收获，想发到这里来和大家交流下。
昨天把RC的题目总结完了，刚才在看scientific american休息一下，然后就开始想我要是gmac会怎么出题。自己出了几道，大家复习累了也可以来试着自己出题玩一下当休息了。文章我已经按G爸爸的思路调整过了。注意超链接我没去掉。编了一个正确答案一个陷阱答案。
Dentalerosion is one of the most common tooth problems in the world today. Fizzydrinks, fruit juice, wine, and other acidic food and drink areusually to blame, although perhaps surprisingly the way we clean our teeth also plays a role. This all makes it soundlike a rather modern issue. But research suggests actually humans have beensuffering dental erosion for millions of years. Recently, researchers havediscovered dental lesions remarkably similar to those caused by modern erosionon two 2.5m year-old front teeth from one of our extinct ancestors. This adds to theevidence that prehistoric humans and their predecessors suffered surprisinglysimilar dental problems to ourselves, despite our very different diets. Thereason may be another unlikely parallel. Erosive wear today is often alsoassociated with aggressive tooth brushing. Australopithecus africanus probably experiencedsimilar dental abrasion from eating tough and fibrous foods. For lesions toform, they would still have needed a diet high in acidic foods. Instead offizzy drinks, this probably came in the form of citrus fruits and acidicvegetables. For example, tubers (potatoes and the like) are tough to eat andsome can be surprisingly acidic, so they could have been a cause of thelesions. Dentalerosion is extremely rare in the fossil record, although this might be becauseresearchers haven’t thought to look for evidence of it until now. But anothertype of problem, carious lesions or cavities, has been found more often infossilised teeth. Cavities are the most common cause of toothache today and arecaused by consuming starchy or sugary food and drink including grains. Theyare often considered a relatively modernproblem linked to the fact that the invention of farming introduced largeamounts of carbohydrates, and more recently refined sugar, to our diets. Butrecent research suggests that cavities have now been found in tooth fossilsfrom nearly every prehistoric hominin species studied. They were probablycaused by eating certain fruits and vegetation as well as honey. These lesionswere often severe, as in the case of cavities found on the teeth of the newly discovered species, Homo naledi. Infact, these cavities were so deep they probably took yearsto form and would almost certainly have caused serious toothache.
Q1 What isthe function of the example of tubers in the first paragraph? A To pointout a type of fruit that is acidic B To mentiona possible cause that might have led to lesions
Q2 It can beinferred from the passage that compared to carious lesions, Dentalerosion, A rarelyexists in tooth fossils B is supportedby less evidence
Q 3according to the recent research, cavities are related to A modern farming B certainfruits and vegetation
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发表于 2018-3-12 00:02:53
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