二、阅读理解
A
体裁: 说明文
主题: 科普知识
难度: ★★★★★
建议用时: 8 min
正确率: /4
It's that time of year when the sun shines warmly, trees get new leaves, and flowers come out. However, for many people, the beauty of spring also brings sneezing, sore skin, and a running nose. Well, spring is the worst allergy(过敏) season.
This is, to a large degree, due to pollen(花粉). When winter ends, plants wake up and start shooting pollen into the air. They can produce billions of these tiny pieces every spring. The pieces get swept up by the wind and land everywhere. It's like a big pollen party in the air!
The problem isn't with pollen itself. This dust-like thing is produced by plants to reproduce and isn't meant to harm(伤害) us. But why do some people have bad reactions to it? It's all because of their immune(免疫) system. The immune system is like a group of soldiers, always ready to fight against harmful things.
Sometimes, the immune system makes a mistake. It thinks pollen is harmful. When this happens, it sends out chemicals(化学物质) that cause allergies, like coughing and sneezing. Why do these allergies get worse? First, pollen only comes in certain seasons, so the immune system can hardly get used to it. Second, the pollen pieces are so small that they easily get into our bodies, making the allergies worse.
Scientists have studied this for a long time. They know genes(基因) play a part. If parents have allergies, their children are more likely to have them. But exactly how do genes lead to allergies? There's no clear answer. Environmental factors also matter. Many scientists believe that growing up in a completely clean environment affects the immune system. But how does this environment affect the start of an allergy? No one can fully explain it.
Most people with seasonal allergies develop them after reaching adulthood. These allergies can change unexpectedly. In some cases, after years of having allergies, they suddenly disappear one spring. But scientists still have no idea how or why this happens.
1. Why does the writer compare(比作) the immune system to soldiers in Paragraph 3?
A. To show why pollen is harmful to the human body.
B. To tell us how pollen brings bad effects to our bodies.
C. To introduce why the immune system makes mistakes.
D. To help readers understand how the immune system works.
2. What makes allergies worse?
A. The immune system knows pollen well.
B. Chemicals cause coughing and sneezing.
C. Pollen appears in different pieces with the seasons.
D. Pollen comes in certain seasons and has tiny pieces.
3. 新趋势·补全文章 Which of the following can be put in the “”?
A. What causes allergies is only genes.
B. How allergies develop is still unknown.
C. What scientists know about allergies matters a lot.
D. How the environment affects allergies is fully understood.
4. What is the best title for this passage?
A. The Role of Pollen in Allergies
B. The Secrets of Spring Allergies
C. The Work of the Immune System
D. The Seasonal Problem of Allergies

二、 A
【语篇解读】本文是一篇说明文。文章主要介绍了春季过敏的原因，包括花粉的作用、免疫系统的反应以及基因和环境因素的影响。
1. D 推理判断题。根据第三段“The immune system is like a group of soldiers, always ready to fight against harmful things.”可知将免疫系统比作士兵，形象说明了免疫系统的防御机制。故选D。
2. D 细节理解题。根据第四段“Why do these allergies get worse? First, pollen only comes in certain seasons ... Second, the pollen pieces are so small that they easily get into our bodies”可知过敏加重的原因是花粉季节性出现导致免疫系统难以适应和微小的花粉颗粒易侵入人体。故选D。
3. B 补全文章题。根据下文“They know genes play a part ... But exactly how do genes lead to allergies? There's no clear answer. Environmental factors also matter ... But how does this environment affect the start of an allergy? No one can fully explain it.”可知本段介绍了基因如何导致过敏尚不明确，环境如何影响过敏未被完全解释，强调过敏成因的未知性；B项“过敏如何发展尚不清楚。”概括了本段的主要内容。故选B。
4. B 标题归纳题。结合文章内容可知，本文主要介绍了春季过敏的原因，包括花粉的作用、免疫系统的反应以及基因和环境因素的影响，但科学界对其成因尚未完全破解。故选B。

【分析】
本题为英语阅读理解题，包含4道不同类型的题目，解题思路如下：
1. 第1题是推理判断题，需定位第三段中“免疫系统比作士兵”的描述，分析比喻的目的，即帮助读者理解免疫系统的工作机制；
2. 第2题是细节理解题，需定位第四段中关于过敏加重原因的表述，匹配选项内容；
3. 第3题是补全文章题，需分析空后段落的核心内容（基因、环境导致过敏的机制尚不明确），选择能概括该内容的选项；
4. 第4题是标题归纳题，需梳理全文主旨（介绍春季过敏的相关原因及未解之谜），提炼最贴合的标题。
【解析】
1. 第1题：根据第三段原文“The immune system is like a group of soldiers, always ready to fight against harmful things.”，将免疫系统比作士兵，是为了形象说明免疫系统时刻准备对抗有害物质的工作机制，帮助读者理解其功能，故选D。
2. 第2题：根据第四段“Why do these allergies get worse? First, pollen only comes in certain seasons, so the immune system can hardly get used to it. Second, the pollen pieces are so small that they easily get into our bodies”，明确过敏加重的两个原因对应选项D的表述，故选D。
3. 第3题：空后段落提到基因如何导致过敏无明确答案，环境对过敏的影响也未完全解释，核心是说明过敏发展的机制尚不明确，B项“过敏如何发展尚不清楚”能概括该内容，故选B。
4. 第4题：全文围绕春季过敏展开，介绍了花粉、免疫系统的作用，以及基因、环境因素的影响，同时提到诸多未解之谜，核心是揭秘春季过敏的相关情况，B项“春季过敏的秘密”最贴合主旨，故选B。
【答案】
二、A
1. D
2. D
3. B
4. B
【知识点】
英语阅读理解、细节理解题、推理判断题
【点评】
本文是一篇关于春季过敏的科普说明文，题目类型涵盖细节理解、推理判断、补全文章及标题归纳，考查学生对文章细节的定位能力、逻辑推理能力和主旨归纳能力，需要学生准确把握原文信息及上下文逻辑，整体难度适中但涉及科普类词汇，对学生的阅读理解能力有一定要求。
【难度系数】
0.4