剑桥雅思10TEST3 PASSAGE2阅读解析

1.     难度分析：难
   

2.     文章标题：Autumn leaves 秋天的叶子
   

3.     文章话题：生物类
   

4.     词汇准备：
   

A段 词性 解释
captivating a. 迷人的，有魅力的
magnificent a. 华丽的
B段
chlorophyll n. 叶绿素
molecule n. 分子
hemisphere n. 半球
evergreen a. 常绿的
conifer n. 针叶林
photosynthesis n. 光合作用
redundant a. 多余的
precious a. 珍贵的
dismantle v. 拆除
valuable a. 有价值的
nitrogen n. 氮
unmask a. 揭露
maple n. 枫树
sumac n. 漆树
C段
anthocyanin n. 花青素
spectrum n. 光谱
flavonoid n. 黄酮类
mint v. 铸造
D段
tolerance n. 容忍
outweigh v. 超过
anti-herbivore a. 抗蚜的
Anti-fungal a. 抗菌的
E段
insect n. 害虫
robust a. 强健的
defense n. 防卫
duller a. 呆滞的
F段
paradox n. 悖论
supreme a. 最高的
pigment n. 色素
salvage v. 抢救
G段
exquisite a. 精致的
overwhelm v. 淹没，压倒
nutrient a. 营养的
deficiency n. 缺陷
oversensitivity n. 过敏
vulnerable a. 易受伤害的
H段
suspect v. 怀疑
clue n. 线索
I段
spectacular a. 壮观的 5. 题型分析：文章题型由三个题型组成：单项选择题+句子配对题+判断题，都是细节题型。

6.  题目解析：
   

Questions 14-18 段落信息配对题

14. a description of the substance responsible for the red colouration of leaves
    题解：题目的意思是一种对叶子产生红色的物质的描述，定位在C段首句：the source of the red is widely known: it is created by anthocyanin,所以答案选择C。
15. the reason why trees drop their leaves in autumn
    题解：题干定位drop leaves in autumn在B段第六行：the tree saves its precious resources and discards them 树节省了资源并且把他们丢弃，所以选择B。
16. some evidence to confirm a theory about the purpose of the red leaves
    题解：题目的意思是证明红叶目的的理论证据，出现在H段第二行：there are clues out there.所以选择H。
17. an explanation of the function of chlorophyll
    题解：题目的意思是对叶绿素功能的解释，定位在B段第一行：the molecule that captures sunlight and converts that energy into new building materials for the tree，的意思是一种分子用来捕捉阳光并转变成树木成长所需的能量。所以选择B。
18. a suggestion that the red colouration in leaves could serve as a warning signal
    题解：定位在E段第二行：they are healthy and robust and would be easily able to mount chemical defences against infestation，树木是健康和强健的并且能轻松分泌出化学物质来抵抗感染。所以选择E。
    Questions 19-22 句子填空题
    The most vividly colored red leaves are found on the side of the tree facing the 19.
    题解：题目定位most vividely在原文H段第三行the reddest, 所以答案填sun。
    The 20 surfaces of leaves contain the most red pigment.
    题解：题目定位the most red pigment在原文H段第四行the red is brighter,所以答案填upper。
    Red leaves are most abundant when daytime weather conditions are 21 and sunny.
    题解：题目定位and sunny在原文H段第五行intense red colors are dry, sunny days and cool nights,所以答案填dry。
    The intensity of the red color of leaves increases as you go further 22.
    题解：题目定位increases在原文H段倒数第三行get much redder the more north，所以答案填north。
    Questions 23-25判断题
19. it is likely that the red pigments help to protect the leaf from freezing temperatures.
    题解：题目定位在D段第三行increases a leaf’s tolerance to freezing. However there are problems with each of these theories.的意思是增加叶子抵抗寒冷的能力，但是这些理论有很多问题，所以答案选FALSE。
20. the ‘light screen’ hypothesis would initially seem to contradict what is known about chlorophyll.
    题解：题目定位在F段第三行it sounds paradoxical, paradoxical替换contradict所以选择TRUE。
21. leaves which turn colors other than red are more likely to be damaged by sunlight.
    题解：原文没有找到相关信息，所以选择NOT GIVEN。
    Questions 26 单选题
    For which of the following questions does the writer offer an explanation?
    A why conifers remain green in winter
    B how leaves turn orange and yellow in autumn
    C how herbivorous insects choose which trees to lay their eggs in
    D why anthocyanins are restricted to certain trees
    题解：答案选B，定位在B段最后一句this unmasking explains the autumn colours of yellow and orange,这个解释揭露了叶子在秋天变黄变橙。