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C
Do you like delicious blueberries? If so, when you eat next time, take a look at them. Are they really blue?
Not really. Take off the skin(表皮). The inside is white. Rub(摩擦) the inside of a blueberry on a white piece of paper. It is reddish-purple. And if you rub the outside of a blueberry, it gets almost black. But the moment you pick one, it does look blue. Why?
①The first way is through "structural colour". ②The blueberry makes "structural colour" in its own way. ③When the blueberry is fully grown, it is black. ④But a thin layer of wax(蜡层), on the outside of the blueberry, gives it a blue look.
The second is through plant pigments(色素). The pigments on the blueberry skin take in green and yellow light and reflect(反射) blue light. That's why blueberries look blue in our eyes. In fact, there aren't any "true blue" in the plants. We can also see the similar features(特点) on the green leaves.
The blueberry's special colour way is cool. It shows nature's magic. More secrets in our nature are waiting for us to discover(发现)! Now your bowl of blueberries suddenly looks a lot more interesting!
(
A. Before sentence ①.
B. Before sentence ②.
C. After sentence ③.
D. After sentence ④.
(
(
A. why blueberries look blue
B. how blueberries take off the skin
C. why blue is special in the plant world
D. how blueberries taste delicious
(
A. It shows national magic.
B. It has many kinds of fruit.
C. It is too hard to understand.
D. It has many undiscovered things.
Do you like delicious blueberries? If so, when you eat next time, take a look at them. Are they really blue?
Not really. Take off the skin(表皮). The inside is white. Rub(摩擦) the inside of a blueberry on a white piece of paper. It is reddish-purple. And if you rub the outside of a blueberry, it gets almost black. But the moment you pick one, it does look blue. Why?
①The first way is through "structural colour". ②The blueberry makes "structural colour" in its own way. ③When the blueberry is fully grown, it is black. ④But a thin layer of wax(蜡层), on the outside of the blueberry, gives it a blue look.
The second is through plant pigments(色素). The pigments on the blueberry skin take in green and yellow light and reflect(反射) blue light. That's why blueberries look blue in our eyes. In fact, there aren't any "true blue" in the plants. We can also see the similar features(特点) on the green leaves.
The blueberry's special colour way is cool. It shows nature's magic. More secrets in our nature are waiting for us to discover(发现)! Now your bowl of blueberries suddenly looks a lot more interesting!
(
A
)18. Where should this sentence "There are two ways to make colours." go in Paragraph 3?A. Before sentence ①.
B. Before sentence ②.
C. After sentence ③.
D. After sentence ④.
(
C
)19. Which of the following probably shows why a leaf looks green to us?(
A
)20. The author writes the passage mainly to tell us .A. why blueberries look blue
B. how blueberries take off the skin
C. why blue is special in the plant world
D. how blueberries taste delicious
(
D
)21. What does the author infer about nature in the end?A. It shows national magic.
B. It has many kinds of fruit.
C. It is too hard to understand.
D. It has many undiscovered things.
答案
C
【文章大意】本文是一篇说明文，揭示了蓝莓呈现蓝色的科学原理——通过表皮蜡层的“结构色”和植物色素的吸光特性共同作用，展现了自然界色彩形成的精妙机制。
18. A 推理判断题。根据第三段中的“The first way is through ‘structural colour’.”和第四段中的“The second is through plant pigments.”可知，这两段介绍了蓝莓呈现蓝色的两种方法，此句表示“颜色可以通过两种方式形成。”应放在句①之前引出下文。故选 A。
19. C 推理判断题。根据文章“The pigments on the blueberry skin take in green and yellow light and reflect blue light. That's why blueberries look blue in our eyes ... We can also see the similar features on the green leaves.”可知，蓝莓表皮的色素会吸收绿光和黄光，同时反射蓝光，因此在我们眼中呈现蓝色，类似的显色特性也存在于绿叶中。由此可知叶子呈现绿色是因为色素吸收了其他颜色的光并反射绿光，与选项 C 的图示逻辑一致。故选 C。
20. A 主旨大意题。根据全文内容，尤其是第二段的“Why?”和后续对蓝莓颜色形成原理的解释可知，文章主要解释蓝莓看起来是蓝色的原因。故选 A。
21. D 细节理解题。根据文章最后一段“More secrets in our nature are waiting for us to discover!”可知，作者推断自然界还有许多未被发现的奥秘。故选 D。
【文章大意】本文是一篇说明文，揭示了蓝莓呈现蓝色的科学原理——通过表皮蜡层的“结构色”和植物色素的吸光特性共同作用，展现了自然界色彩形成的精妙机制。
18. A 推理判断题。根据第三段中的“The first way is through ‘structural colour’.”和第四段中的“The second is through plant pigments.”可知，这两段介绍了蓝莓呈现蓝色的两种方法，此句表示“颜色可以通过两种方式形成。”应放在句①之前引出下文。故选 A。
19. C 推理判断题。根据文章“The pigments on the blueberry skin take in green and yellow light and reflect blue light. That's why blueberries look blue in our eyes ... We can also see the similar features on the green leaves.”可知，蓝莓表皮的色素会吸收绿光和黄光，同时反射蓝光，因此在我们眼中呈现蓝色，类似的显色特性也存在于绿叶中。由此可知叶子呈现绿色是因为色素吸收了其他颜色的光并反射绿光，与选项 C 的图示逻辑一致。故选 C。
20. A 主旨大意题。根据全文内容，尤其是第二段的“Why?”和后续对蓝莓颜色形成原理的解释可知，文章主要解释蓝莓看起来是蓝色的原因。故选 A。
21. D 细节理解题。根据文章最后一段“More secrets in our nature are waiting for us to discover!”可知，作者推断自然界还有许多未被发现的奥秘。故选 D。
解析
【分析】
本题为英语阅读理解题，需结合文章内容及题目类型逐一分析：
1. 第18题是句子插入题，需梳理段落逻辑，找到能引出两种显色方式的位置；
2. 第19题是推理判断题，需根据文章中蓝莓显色的原理，推导叶子显绿色的原因；
3. 第20题是主旨大意题，需概括全文核心内容；
4. 第21题是细节理解题，需定位文章最后一段的关键信息。
【解析】
1. 第18题：文章第三段介绍第一种显色方式（结构色），第四段介绍第二种（植物色素），插入句“There are two ways to make colours.”用于引出两种方法，应放在句①之前，故选A。
2. 第19题：根据文章“蓝莓表皮色素吸收绿和黄光，反射蓝光”，绿叶的显色特性类似，即吸收其他光、反射绿光，对应选项C的图示逻辑，故选C。
3. 第20题：全文围绕“蓝莓看起来是蓝色的原因”展开，从结构色和植物色素两方面解释，核心是说明蓝莓显蓝的原因，故选A。
4. 第21题：文章最后一段提到“More secrets in our nature are waiting for us to discover!”，对应选项D“自然界有许多未被发现的事物”，故选D。
【答案】
18.A 19.C 20.A 21.D
【知识点】
阅读理解（句子插入、推理判断、主旨大意、细节理解）
【点评】
本文是一篇介绍蓝莓显色原理的说明文，题目类型全面，需学生准确把握文章结构、细节及逻辑关系，结合题干要求定位信息解题，整体难度适中。
【难度系数】
0.6
本题为英语阅读理解题，需结合文章内容及题目类型逐一分析：
1. 第18题是句子插入题，需梳理段落逻辑，找到能引出两种显色方式的位置；
2. 第19题是推理判断题，需根据文章中蓝莓显色的原理，推导叶子显绿色的原因；
3. 第20题是主旨大意题，需概括全文核心内容；
4. 第21题是细节理解题，需定位文章最后一段的关键信息。
【解析】
1. 第18题：文章第三段介绍第一种显色方式（结构色），第四段介绍第二种（植物色素），插入句“There are two ways to make colours.”用于引出两种方法，应放在句①之前，故选A。
2. 第19题：根据文章“蓝莓表皮色素吸收绿和黄光，反射蓝光”，绿叶的显色特性类似，即吸收其他光、反射绿光，对应选项C的图示逻辑，故选C。
3. 第20题：全文围绕“蓝莓看起来是蓝色的原因”展开，从结构色和植物色素两方面解释，核心是说明蓝莓显蓝的原因，故选A。
4. 第21题：文章最后一段提到“More secrets in our nature are waiting for us to discover!”，对应选项D“自然界有许多未被发现的事物”，故选D。
【答案】
18.A 19.C 20.A 21.D
【知识点】
阅读理解（句子插入、推理判断、主旨大意、细节理解）
【点评】
本文是一篇介绍蓝莓显色原理的说明文，题目类型全面，需学生准确把握文章结构、细节及逻辑关系，结合题干要求定位信息解题，整体难度适中。
【难度系数】
0.6
