Question

12．It's never a real problem for us when the weather gets cold．  We have many different ways of coping with the cold．We can put on more clothes，stay next to a fireplace，turn on the air conditioner or simply travel to a warmer city to spend the winter．But things are not as easy for plants．Unlike humans，plants can't move to escape the cold or generate heat to keep themselves warm．So how do they manage to survive the freezing winter？
    The cold is a big challenge for plants．Their living tissues can be damaged when they freeze．It's like a plant's equivalent（相等物）to frostbite（冻疮）．Also，the process of freezing and thawing（解冻）can cause air bubbles to form in the plant's water transport system．If enough of these air bubbles come together as water thaws they can block the flow of water from the roots to the leaves and kill the plant．
    To live through cold weather，plants have developed three strategies，Some plants，such as oak trees，avoid freezing damage by dropping their leaves，before the winter chill sets in-effectively shutting off the flow of water between roots and leaves-and growing new leaves and water transport cells when the warm spring returns．Other plants，pine trees for example，protect them-selves by narrowing their water transport cells，which makes it easier for cells to travel among air bubbles．The third strateg is also the most extreme．Some plants； die on the ground in winter and start growing as new plants from seeds when conditions get warmer．
    However，these smart strategies were developed very slowly-over millions of years of evolution．This leads scientists to worry that plants may not be able to deal with human-caused climate change，which has only started occurring over the past few decades．Scientists are hoping to find possible ways to save plants from the threat of climate change．

51．What is the text mainly about？B
A．Different ways for people to keep warm．
B．How plants live through the freezing winter．
C．How plants develop the 8tratef；ies to keep warm*
D．The ways to save plants from the cold，
52．If the water transport from roots to leaves is blocked，D．
A．the plant will suffer from f'rostbite
B．air bubbles will be formed
C．the plant's living tissues will be damaged
D．the plant will be killed
53．Oak trees protect themselves byA．
A．stopping the water transport from roots to leaves
B．dropping their leaves to grow seeds
C．slowing the flow of water from roots to leaves
D．storing enough water in the roots
54．What does the underlined phrase"sets in"mean in Paragraph3？B
A．stops       
B．begins      
C．leaves      
D．returns
55．What is the main idea of the last paragraph？C
A．Plants can，easily adapt to climate change．
B．Scientists are making efforts to save plants．
C．Climates change is a great threat to plants．
D．Plants are developing new strategies to survive．

Answer 1

分析 在寒冷的冬天，人们有各种各样保暖的方法，但是植物怎么过冬呢？这篇文章讲的是植物在寒冷的天气生存的方法．

解答 51．答案 B 主旨归纳题 从全篇文章和第二段的句子：But things are not as easy for plants．Unlike humans，plants can't move to escape the cold or generate heat to keep themselves warm．So how do they manage to survive the freezing winter？可知这篇文章讲的是植物在寒冷的天气生存的方法，故答案为B
52．答案 D 细节理解题 根据If enough of these air bubbles come together as water thaws they can block the flow of water from the roots to the leaves and kill the plant．
可知，如果运输通道堵塞，植物就会死掉，故答案为D
53．答案 A 细节理解题：从第五段的句子：Some plants，such as oak trees，avoid freezing damage by dropping their leaves before the winter chill sets in-effectively shutting off the flow of water between roots and leaves 可知橡树是通过在冬天将树叶落下，这样来在冬天幸存的，选A．
54．答案 B 词义猜测题 根据句意Some plants，such as oak trees，avoid freezing damage by dropping their leaves before the winter chill sets in…可知，set in 此处的意思是"开始"故答案为B
55．答案 C 主旨归纳题  根据文章倒数第二段的句子：This leads scientists to worry that plants may not be able to deal with human-caused climate change，which has only started occurring over the past few decades．可知科学家担心的是人类造成的气候变化对植物来说是个威胁．

点评 阅读理解题主要考查考生对书面语篇的整体领悟能力和接受及处理具体信息的能力．试题的取材，密切联系当前我国和世界经济、科技等方面的变化，有关数据的来源真实可信．因此科普知识类文章是每年的必考题．分析历年的科普类文章我们不难发现以下特点：
1、文章逻辑性强，条理清楚，语法结构简单，用语通俗．
2、文章内容注重科技领域的新发现．内容新颖，从而使文章显得陌生，内容抽象复杂．
3、命题方面注意对具体细节的准确理解和以之为依据的推理判断．
4、以人们的日常行为或饮食健康入手，探讨利弊，诠释过程，阐述概念．