托福

　　托福阅读推理题是托福阅读中有点难度的题型，考生首先要找到原文中的信息，然后需要在这些信息的基础上进行合理推测，很多考生可能都不熟悉这类题型的做法。前程百利小编为大家带来托福阅读推理题的逆向推理法，希望对大家有所帮助。

　　托福阅读推论题是需要依靠原文信息来进行逻辑推理的，所以会出现正向思维推理和逆向思维推理。原文信息出现对比，已知两个事物(时间)的不同之处和其中一个事物(时间)的特点，然后推理另一个事物(时间)的特点就属于逆向推理。比如TPO2中的The Origins of Cetaceans 的第2题，可以利用事物之间的对比逆向推理：

　　Paragraph 1: It should be obvious that cetaceans—whales, porpoises, and dolphins—are mammals. They breathe through lungs, not through gills, and give birth to live young. Their streamlined bodies, the absence of hind legs, and the presence of a fluke1 and blowhole2 cannot disguise their affinities with land dwelling mammals. However, unlike the cases of sea otters and pinnipeds (seals, sea lions, and walruses, whose limbs are functional both on land and at sea), it is not easy to envision what the first whales looked like. Extinct but already fully marine cetaceans are known from the fossil record. How was the gap between a walking mammal and a swimming whale bridged? Missing until recently were fossils clearly intermediate, or transitional, between land mammals and cetaceans.

　　题目：Which of the following can be inferred from paragraph 1 about early sea otters?

　　○It is not difficult to imagine what they looked like.

　　○There were great numbers of them.

　　○They lived in the sea only.

　　○They did not leave many fossil remains.

　　解析：题目需要推测关于early sea otters的，回到原文中定位到句子“However, unlike the cases of sea otters and pinnipeds (seals, sea lions, and walruses, whose limbs are functional both on land and at sea), it is not easy to envision what the first whales looked like.“，句中存在着一个unlike，这里出现了对比，对比的是”the cases of sea otters and pinnipeds “以及前面的”cetaceans”，所以这里题目让推理其中一方的特征，我们只要关注另一方有什么特征然后逆推就可以了。其实从本句就可以看出”cetaceans”的特征是”不容易看出之前的样子”，所以答案肯定是反向的，也就是选项A。当然如果定位句中并没有直接提及特征，我们还需要把关于”cetaceans”的信息都看一下，从前面关于它的内容中总结出其他特征。

　　再比如TPO4Petroleum Resources中的推理题，可以利用时间关系对比来解题。

　　Paragraph 3: Oil pools are valuable underground accumulations of oil, and oil fields are regions underlain by one or more oil pools. When an oil pool or field has been discovered, wells are drilled into the ground. Permanent towers, called derricks, used to be built to handle the long sections of drilling pipe. Now portable drilling machines are set up and are then dismantled and removed. When the well reaches a pool, oil usually rises up the well because of its density difference with water beneath it or because of the pressure of expanding gas trapped above it. Although this rise of oil is almost always carefully controlled today, spouts of oil, or gushers, were common in the past. Gas pressure gradually dies out, and oil is pumped from the well. Water or steam may be pumped down adjacent wells to help push the oil out. At a refinery, the crude oil from underground is separated into natural gas, gasoline, kerosene, and various oils. Petrochemicals such as dyes, fertilizer, and plastic are also manufactured from the petroleum.

　　题目：Which of the following can be inferred from paragraph 3 about gushers?

　　○They make bringing the oil to the surface easier.

　　○They signal the presence of huge oil reserves.

　　○They waste more oil than they collect.

　　○They are unlikely to occur nowadays.

　　解析：答案是D,可以定位到句子“Although this rise of oil is almost always carefully controlled today, spouts of oil, or gushers, were common in the past.“这个句子中有明确的两个时间概念today和in the past，两者之间有对比，句子明确说明”以前“gushers是常见的，所以可以逆推”现在“应该不常见，正好对应选项D。

　　以上就是前程百利小编为大家带来的托福阅读推理题解题的相关介绍，要提醒考生的是，其实有很大一部分推理题都是利用逆向推理来解决的，正向推理的情况较少见，所以希望大家可以总结更多相关方法。预祝大家托福考试取得好成绩!