题目内容
IT’S never a real problem for us when the weather gets 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 – people have many different ways of coping with the cold.
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?
It turns out that plants have their own strategies too, said a study published on Dec 22 in the journal Nature.
According to researcher Amy Zanne of George Washington University, US, the cold is a big challenge for plants. Their living tissues can be damaged when they freeze. “It’s like a plant’s equivalent to frostbite (冻疮),” Zanne told Science Daily. 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,” she explained.
To live through cold weather, plants have developed three traits, according to the study. 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 themselves by narrowing their water transport cells, which makes it easier for cells to travel among air bubbles.
The third strategy 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, the study also found that 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 that this study can help people find possible ways to save plants from the threat of climate change.
1.What is the article mainly about?
A. Why plants are not afraid of the winter chill.
B. The ways that plants survive cold weather.
C. Changes in plants’ water transport system in winter.
D. How plants evolve to keep up with climate change.
2.According to the article, if a plant freezes in the winter, ______.
A. it produces more living tissues to stay alive
B. its leaves quickly fall out and its roots begin to die
C. lots of air bubbles form in its water transport system
D. its water transport system could be blocked in the spring
3.How do oak trees usually survive the cold winters?
A. By dropping their leaves before winter.
B. By narrowing their water transport cells.
C. By widening their water transport cells.
D. By leaving only the seeds alive and growing from the seeds in the spring.
4.What are scientists worried about when it comes to plants according to the article?
A. Plants may not be able to adapt to the increasingly cold climate.
B. Human activities might have a great impact on the pace of plants’ evolution.
C. Plants may not be able to evolve fast enough to adapt to human-caused climate change.
D. The strategies plants develop are not good enough to protect them against cold.
1.B
2.D
3.A
4.C
【解析】
试题分析：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。
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考点：考查科普类短文
尖子生新课堂课时作业系列答案请认真阅读下面短文，并根据所读内容在文章后表格中的空格里填上一个最恰当的单词。注意：请将答案写在答题纸上。
Talking to friends on WeChat, Wang Chenchen’s mood changes according to her friends’ replies. Long sentences are always heartwarming and happy emoticons indicate the other person’s good spirits. But one word replies like “OK”, “Oh” or “hehe” quickly kill the mood.
Over-reliance on online communication is causing division between people and social anxiety in this digital era. With social media bringing people closer together than ever before, a new set of online language norms also appears.
Connected or separated
Wang Chenchen, 20, an English major at the University of International Business and Economics says, “I tend to judge my friends by the quality and speed with which they comment on my updates on Weibo or WeChat.”
But to Chen Jie, 21, a biological engineering major at Huazhong University of Science and Technology, Wang’s evaluation system is problematic. “Everyone has their lifestyle and a certain way of using social media,” says Chen, who is always busy working in the laboratory and hardly has time for social media.
Ge Yan, a professor of communication at Shanghai Jiaotong University, says social media is causing fragmentation (碎片化) of communication. “People tend to judge their surroundings by the information available,” says Ge. “They also evaluate their friendships and others’ lifestyles based on fragmented pieces of information with which they construct a so-called reality.”
Need for emotion
According to Ge, such superficial communication helps encourage more interaction between people, but in terms of building solid interpersonal relationships it causes more harm than good. An online survey on Sina Weibo last month shows, “hehe” was the top conversation killer in 2013. “The words people hate all have one thing in common — a lack of emotion,” says Ge.
Zhang Wei, a professor of linguistics at Renmin University of China, thinks that such short expressions carry so little emotion that they separate people. Chatting online cannot convey the same emotions as communication in real life. This makes it difficult to understand the other person’s true intentions. “That’s why I always suggest talking face to face to resolve problems,” says Zhang. “Unfortunately the reality is that most people spend less time talking to each other in this way.”
Anxiety and insecurity
Zhang further explains that the reason why people’s mood is strongly affected by such unemotional words when communicating online is rooted in social anxiety. People feel insecure because of all kinds of pressures. It’s like a vicious circle — “Less time for face-to-face communication leads to more online communication, but online expressions of emotion are too changeable to provide the comfort needed,” says Zhang. “As a result, people become more anxious.”
Title | Conversation killers | |
Problems | People’s mood is easily affected by unemotional words while communicating online. In this digital era, people are feeling more separated, (1) ________ and insecure than ever before. | |
Reasons | People (2) ________ on online communication too much. Online talkers start to (3) ________ a new set of online language norms. | |
Name | (4)________ | What they say and think |
Wang Chenchen | An English major | I tend to judge a friend by how well and how (5) ________ they reply to my updates on Weibo or WeChat. |
Chen Jie | A biological engineering major | Wang’s evaluation system doesn’t hold water because different people have different (6) ________ and different ways of using social media. |
Ge Yan | Professor of communication | Incomplete (7) ________ can’t be used to evaluate people’s friendships, and superficial communication does harm to interpersonal relationships. People’s (8) ________ for short and careless replies like “hehe” arises from their lack of emotion. |
Zhang Wei | Professor of linguistics | Those unemotional expressions (9) ________ the gap between people. My (10) ________ is that people should talk face to face though busy. |
