Sentence Completion 解析2

●Passage分析

A. Man mainly uses his sense of sight, while dogs primarily use their sense of smell.As many people and families have dogs as pets these days, and since dogs are now employed in many activities, it is best to understand how canines interpret the world using their noses.

B. In man, the most highly developed section of the brain is the visual cortex.Conversely, the olfactory cortex is the most advanced in dogs.Canines'scent receptors can range from 125 million to 300 million；whereas man only has about 5 million.Any odor, therefore, is a hundred million times stronger when being smelled by a dog.Many people today use dogs in various kinds of work because of their sharp sense of smell.In many places around the world, dogs are used in search and rescue operations, drug and illegal merchandise detection, or the sensing of smuggled goods, like concealed agricultural and meat products, and even humans.In medicine, there are studies that focus on dogs'abilities to find certain types of tumors.For working dogs, the breed is not as important as temperament and intelligence.Hence, a working dog can either be a pure or mixed breed.However, larger dogs are preferred to smaller breeds, particularly if the line of work involves walking long distances, climbing or jumping over high areas, or guarding.

C. The dog's unique talents can be used in various ways.Most of all, dogs are valuable members of society that do serve their communities in a number of significant ways.

·段落A：开头提出与主要使用视觉的人类不同，狗主要使用的是嗅觉。

·段落B：从生物学方面说明狗的嗅觉发达的程度。同时，通过具体事例（探测走私品、发现肿瘤等），说明在日常生活中狗的嗅觉是如何被利用的。同时指出体形大的狗更有利于完成这些任务。

·段落C：再次强调狗发达的嗅觉在多方面起到积极作用。

●Question　分析与答案

1.A dog's brain is governed by the___，whereas man's brain is controlled by the visual cortex.

2.A dog's keen___is valued by many people, particularly those who are involved in search and rescue operations and the detection of drugs or illegal goods.

3.Breed is not an issue when training working dogs；but normally，___are selected instead of petite ones.

需要理解有关狗嗅觉的生物特性以及狗的嗅觉具体利用在哪个方面。这些内容都在段落B被提及。

词汇巩固primariIy优先　canine犬的　interpret解释，说明　cortex皮层，外皮　converseIy相反地　oIfactory嗅觉的scent香味，气味　receptor感觉器官　rescue营救，救援　merchandise商品　detection探测　smuggIe走私conceaI隐藏　agricuIturaI农业的　tumor肿瘤　particuIarIy特别地，格外