考GRE的时候，你可以相信什么?

数学里你可以相信的

对于这个问题，官方指南上之前就明确说过，在解析几何里，图都是标准的。Coordinate systems, such as xy-planes and number lines, are drawn to scale. Therefore, you can read, estimate, or compare quantities in such figures by sight or by measurement, including geometric figures that appear in coordinate systems. 其实如果不按标准来画，连第一第三象限，是否过原点这些信息都不能提供的话，画个图干嘛呢?一般对于图形来说，定性的问题，比如相对位置，是不重合的点，是直线，是三角形，这些都是可以相信的，但定量的问题，比如处在两点之间，但相距多远不确定，是三角形，但到底是直角、钝角还是锐角三角形是不确定的。

Points, lines, angles, etc., that are shown as distinct are indeed distinct…
Geometric figures are not necessarily drawn to scale. That is, you should not assume that quantities such as lengths and angle measures are as they appear in a figure. However, you should assume that lines shown as straight are actually straight, and when curves are shown, you should assume they are not straight.

更多关于GRE数学可以相信或者预设的东西，可以在OG里搜“conventions”这个词找到。

阅读里你可以相信的

在GRE阅读里面，即便是逻辑题，你也可以相信作者当成事实说出来的基本前提。而if true类的题选项提供信息和原文事实之间一定是兼容的，所以在理解选项的时候要在给定事实的限定之下来理解。

比如这个题

Between 1970 and 1980, energy consumption by United States industry peaked and then declined, so that by 1980 total industrial use of energy was below the 1970 level even though total industrial output had grown substantially in the same period. Industry must have instituted highly effective energy conservation measures in those years to have achieved such impressive results.

题目要求削弱，答案是The industries whose production dropped sharply during the 1970s included a disproportionately large number of energy-intensive industries.具体视频讲解可以在题库搜到。但有同学就觉得这选项跟原文信息矛盾了，原文明确说这段时间产出变高，选项说产出下降。但我们知道if true削弱题不会直接矛盾，那会不会说的不是同一个产出?原文说的是工业界总产出，选项说的是产出急剧下降的那些工业/企业如何如何。总的工业产出变高，但其中部分企业产出急剧下降，这不矛盾。

还有这个题

A recent study shows that farmers have a 40 percent lower risk of developing various common forms of cancer than people in the general population do. Farmers are more active than most people are, but even taking this into account, farmers had a significantly lower cancer risk. Therefore, it is likely that some substances that farmers are typically exposed to in the course of their work lower the risk of developing these forms of cancer.

题目要求削弱，答案是In the group that remains after urban dwellers are eliminated from the study's sample, the risk of developing cancer is the same for farmers and nonfarmers. 具体解析可以在题库搜到。但有同学就觉得排除城市居民以后，不就只剩下农民了吗，为什么还有农民和非农民之分?首先我们要对ETS有基本的信任，在if true里，它说有，那就真是有，或者劝劝自己，它的意思是假设有的话能不能削弱原文论证，现实世界中是不是真的排除城市居民之后还有农民和非农民之分，这不重要。其次，如果因为抱持着这个选项不具有现实可能性，意思很荒谬就排除的话，这题会不会有点太简单了，跟原文和题目有什么关系呢?阅读题的选项就算是错，也不会仅仅因为选项孤立地看有逻辑错误或者意思很荒谬而错，要错一定是因为要么原文不支持，要么不符合题目要求。如果觉得意思荒谬，那可能是没读懂选项字面意思或者语境里的含义。在理解选项的时候，要注意语法、语义和语境的合理性。

填空里你可以相信的

填空原文可以相信。ETS很少, if ever, 会在作者原词和其他选项之间不选原词。如果觉得人家写得不好，不要挑这个句子来出题就行了，没必要去改别人用词。