GMAT备考，除了背背背，更重要的就是练练练！通过练习，巩固知识，熟练技巧，最终才能在GMAT考试中发挥出色，取得好成绩，所以练习的重要性不言而喻。因此，小编为大家精心准备了GMAT考试各类题型的练习题和答案解析，帮助大家每日一练，为考试做好准备。一起来看今天的题目。
今日练习题为阅读题，题目如下
Most farmers attempting to control slugs and snails turn to baited slug poison, or molluscicide, which usually consists of a bran pellet containing either methiocarb or metaldehyde. Both chemicals are neurotoxins that disrupt that part of the brain charged with making the mouth move in a coordinated fashion - the "central pattern generator" - as the slug feeds. Thus, both neurotoxins, while somewhat effective, interfere with the slugs' feeding behavior and limit their ingestion of the poison, increasing the probability that some will stop feeding before receiving a lethal dose. Moreover, slugs are not the only consumers of these poisons: methiocarb may be toxic to a variety of species, including varieties of worms, carabid beetles, and fish.
Researchers are experimenting with an alternative compound based on aluminum, which may solve these problems, but this may well have a limited future as we learn more about the hazards of aluminum in the environment. For example, some researchers suggest that acid rain kills trees by mobilizing aluminum in the soil, while others have noted that the human disease Alzheimer's is more prevalent in areas where levels of aluminum in the soil are high. With farmers losing as much as 20 percent of their crops to slugs and snails even after treatment with currently available molluscicides, there is considerable incentive for researchers to come up with better and environmentally safer solutions.
1. In the passage, the author is primarily concerned with
A describing the limitations of molluscicides that affect feeding behavior
B proposing alternatives to current methods of controlling slugs and snails
C emphasizing the need for an alternative to currently available molluscicides
D explaining how molluscicides are used to control slugs and snails
E criticizing the use of hazardous material for controlling slugs and snails
2. The author suggests that which of following is true of the "alternative compound" mentioned in the highlighted text?
A It is more effective in destroying snails than in destroying slugs.
B It begins to affect slugs' feeding behavior before they ingest a lethal dose.
C It affects more species of fish than does metaldehyde.
D It may not be environmentally safer than methiocarb.
E It may be less damaging to trees than metaldehyde.
3. The author cites which of the following as a disadvantage of methiocarb?
A It contains high levels of aluminum.
B It may react with acid rain to kill trees.
C It has been associated with Alzheimer's disease.
D It may be toxic to some species of fish.
E It may not be as effective in killing slugs as metaldehyde is.
4. The passage suggests that methiocarb and metaldehyde would be more effective as slug poisons if it were true that they
A disrupt the slug's digestive processes rather than its reproductive functions
B reduce the slug's ability to taste food
C begin to affect the feeding behavior of a slug only after it has ingested a lethal dose
D reach the central pattern generator more quickly
E accumulate only in the central pattern generator rather than throughout the brain
正确答案：
C,D,D,C
文章分析：
很多农夫试图用鼻涕虫毒药来控制鼻涕虫和蜗牛----这个方法效果并不是很好----提出了新的方法，用铝----但是也还是有很大问题----需要新的方法
这是一篇比较简单的短文章，虽然开始有许多可能不认识的词汇，但是不影响理解整个文章的主旨。
第一题
这道题目可能有些难选，因为作者通篇看似讲了两个消灭鼻涕虫的方法，其实一个是现有的方法，因为这个方法不好，迫切需要改进，所以又有人提出的另一个新的方法，可是新方法的缺陷也十分严重，结尾作者这样的情况刺激研究员找出新方法。但是这道题想要直奔答案选项不很容易，用排除法可以顺利解题。
选项分析：
A 描述影响饮食能力的软体动物驱除药的限制条件。这个内容属于第一段描述的内容，不是全文的主旨，是细节。
B 提出控制鼻涕虫和蜗牛的另一种方法。这个选项容易误选。作者确实提出了令一个方法，但是作者反驳了这个方法并在结尾说需要其他的方法，说明作者不是为了提出第二个方法才写的文章。
C Correct. 强调现在的软体动物驱除药需要改变。其实作者一开篇就强调说现在的方法不好，进而说新的方法也不好，需要别的方法。所以作者的目的是要强调需要另外的方法。
D 解释软体动物驱除药是如何控制鼻涕虫和蜗牛的。这也属于第一段的内容，不是全文的主旨。
E 批评用有危险的材料来控制鼻涕虫和蜗牛。作者提出了两个方法都有危险，但是没有批评这两个方法的意思，只是单纯的陈述说这两个方法不行。
第二题
第二段提到的替代品中的哪项描述是正确的。
选项分析：
A 杀蜗牛比杀鼻涕虫更有效。 错，没有提到。
B 在鼻涕虫摄入致死剂量的农药前便开始影响他们的进食行为。错，指的是第一段提到的两种农药，并非第二段的替代品。
C 比metaldehyde影响到的鱼种类更多。错。第一段中提到的影响鱼类与第二段的这种替代品没有关系。
D 可能在对自然环境的影响上并不比methiocarb更安全。正确，第二段主要就是在讲这种替代品的一些污染环境，比如酸雨或者疾病之类的副作用。
E metaldehyde是否会损害树木未知，无从比较。
第三题
选项分析：
A 它含有大量的铝。第二段开篇就说了，含有铝的化合物可以解决问题。如果“methiocarb”中有铝，就不会有第一种方法的问题，也不会提出第二个方法了。
B 它会和酸雨反应杀死树木。文中只提到了酸雨本身可以杀死树木，没有提及什么和酸雨一起作用杀死树木。
C 它和“Alzheimer”这种病有关。文中提到，“Alzheimer”是和大量的铝有关的。由“A”可知，“methiocarb”中没有大量的铝。
D Correct. 它可能会对某些种类的鱼有毒。几乎是定位句的直译。
E 它可能在杀鼻涕虫方面没有“metaldehyde”那么有效。文中没有比较过这两者的杀虫能力。
第四题
题目的意思其实让我们找出这两者的劣势，然后反过来就是答案了。定位在“Thus, both neurotoxins, while somewhat effective, interfere with the slugs' feeding behavior and limit their ingestion of the poison, increasing the probability that some will stop feeding before receiving a lethal dose.”这两者的问题是鼻涕虫在吃到致命的剂量之前就被影响了饮食表现。所以，如果可以在致命剂量之后才影响饮食表现就可改进。
选项分析：
A 扰乱鼻涕虫的消化过程而不是繁殖功能。根据定位句可知，影响的是饮食表现而不是消化过程。
B 减少鼻涕虫的味觉能力。这个选项有一定的迷惑性。文中也没有提到过“味觉能力”。所以我们无法确认味觉是不是鼻涕虫不吃到致命剂量的原因。所以减少这样的能力不能确定是否会影响鼻涕虫吃到致命的剂量。
C Correct. 只有达到了致命的剂量才开始影响鼻涕虫的饮食表现。考点中已经分析的很清楚了，此处不再赘述。
D 达到“central pattern generator”更快。这个选项说反了，如果更快的达到“central pattern generator”，鼻涕虫饮食表现受到的影响也就更快。
E 只在“central pattern generator”中累积而不是大脑中。不论在哪里累积，只要不能减缓影响饮食表现的时间，就无法让这两者的效果更大。
