Question

11．The crab is a living clock．It tells the time of the day by the colour of its skin，which is dark by day and pale by night．The crab's changing skin colour is a regular twenty-four hour cycle（周期）that follows the daily rhythm（循环）of the sun．
    Does the crab really keep time，or is its skin simply affected by the sun's rays（光线），changing colour with the amount of the sunlight？To find out the answer，scientists kept some crabs in a dark room for two months．Even without daylight the crabs'skin colour continued to change．
    The change probably had something with the rhythm of the sun，to help protect the crab from the sunlight and enemies．After millions of years it has become completely regular inside the living body of the crab．
    Scientists noticed that once each day the colour of the crab is especially dark，and that each day this appears about fifty minutes later than the day before．From this they discovered that each crab follows not only the rhythm of the sun but also that of the tides（潮汐）．The crab's darkest period（一段时间）is the time of low tide on the beach where it is caught．
33．The crab's changing colourB．
A．tells the crab what time it is               
B．protects the crab from the sunlight
C．keeps the crab warm                     
D．gives the crab a lot of energy
34．Scientists studied crabs in order to find outC．
A．why they change colour                   
B．how to use them as clocks
C．whether they change colour                
D．where they can be caught
35．When the crabs were kept in the dark，D．
A．they didn't change colour                   
B．they changed colour more quickly
C．they changed colour more slowly             
D．they changed colour as usual
36．The crab is like a clock because its colour changesA．
A．in a regular 24-hour rhythm           
B．at low tide
C．with the sun's rays                   
D．every fifty minutes．

Answer 1

分析 本文主要向我们介绍了可以作为我们生物钟的螃蟹：它通过它肤色颜色的变化来告诉人们时间，螃蟹的肤色变化是一个规律的二十四小时周期，遵循太阳的日常节奏．为了证实这一点，下文科学家作了实验，即科学家们在黑暗的房间里养了两个月的螃蟹，即使没有光线，螃蟹的肤色也会继续变化．文章作了具体介绍．

解答 33 B 细节理解题：根据第三段The change probably had something with the rhythm of the sun，to help protect the crab from the sunlight and enemies这种变化可能与太阳的节奏有关，帮助保护蟹免受阳光和敌人的伤害．故选B．其余三项均不符合文章的意思．
34 C 细节理解题：根据第二段To find out the answer，scientists kept some crabs in a dark room for two months．Even without daylight the crabs'skin colour continued to change．为了找到答案，科学家们在黑暗的房间里养了两个月的螃蟹，即使没有光线，螃蟹的肤色也会继续变化．故选C．
35 D 细节理解题：根据第二段To find out the answer，scientists kept some crabs in a dark room for two months．Even without daylight the crabs'skin colour continued to change．为了找到答案，科学家们在黑暗的房间里养了两个月的螃蟹，即使没有光线，螃蟹的肤色也会继续变化．故选D．
36 A 细节理解题：根据第一段The crab's changing skin colour is a regular twenty-four hour cycle（周期）that follows the daily rhythm（循环）of the sun．螃蟹的肤色变化是一个规律的二十四小时周期，遵循太阳的日常节奏．故选A．

点评 对考生提出以下几方面要求：1．不但要求掌握所读材料的主旨大意、中心思想，而且要求掌握文章中的详细事实与细节． 2．不但要求对于具体事实情节的理解，而且要求对其抽象含义的理解，既要理解字面意思，又要理解其深层含义，包括作者的态度、观点、意图等． 3．既要求理解文章中某句、某段的含义及全文的逻辑关系，又要求根据其含义及逻辑关系进行判断和推理． 4．既要求考生能够运用材料中的信息去理解、分析问题；又要求考生能运用中学生应有的生活常识去分析、理解问题．