威威老師的閱讀教室：說明文 (Expository Texts)
Section 1：說明文特色 (Features of Expository Texts)
1.1 什麼是說明文？
說明文 (Expository Text) 的目的是提供資訊和解釋概念。和記敘文不同，說明文不是在說故事，而是在告訴你某件事的事實、原因、過程或比較。
1.2 說明文的結構
主題句 (Topic Sentence)
→ 點出這篇文章要介紹什麼
|
├── 支持細節 1 (Supporting Detail)
├── 支持細節 2 (Supporting Detail)
├── 支持細節 3 (Supporting Detail)
|
結論句 (Concluding Sentence)
→ 總結或強調重要性
1.3 說明文的四種常見類型
| 類型 | 功能 | 信號字 |
|---|---|---|
| How-to（操作說明） | 教你怎麼做某事 | first, then, next, finally |
| Cause-Effect（因果關係） | 解釋原因和結果 | because, as a result, therefore, lead to |
| Comparison（比較對比） | 比較兩件事的異同 | similarly, in contrast, however, on the other hand |
| Problem-Solution（問題解決） | 提出問題和解決方案 | the problem is, one solution is, by doing this |
1.4 閱讀說明文的策略
- 讀第一段——掌握主題
- 找信號字——判斷文章類型
- 畫重點——每段的主題句和關鍵細節
- 做總結——用自己的話說明文章大意
Section 2：五篇說明文 (Five Expository Texts)
Text 1：How Dolphins Communicate（海豚如何溝通）
Dolphins are among the most intelligent animals on Earth, and one of the most fascinating things about them is how they communicate with each other. Unlike humans, who use words and sentences, dolphins use a combination of sounds and body language to share information and express their feelings.
The most common way dolphins communicate is through whistles and clicks. Each dolphin has its own unique whistle, called a “signature whistle,” which works like a name. When a dolphin wants to call another dolphin, it will use that dolphin’s signature whistle. Scientists have found that dolphins can remember the signature whistles of their friends even after being separated for many years.
In addition to whistles, dolphins use body language to communicate. They may slap their tails on the water to show anger or excitement, or they may swim close together to show friendship. Leaping out of the water, known as “breaching,” can be a sign of joy or a way to get attention.
Dolphins also use echolocation to navigate and find food. By producing clicking sounds and listening to the echoes that bounce back, they can determine the size, shape, and distance of objects in the water. This ability is especially useful in dark or murky water where visibility is poor.
Understanding dolphin communication helps scientists learn more about these amazing creatures and how we can better protect them and their ocean habitats.
Key Vocabulary
| English | Chinese | 例句 |
|---|---|---|
| intelligent | 聰明的 | Dolphins are very intelligent animals. |
| communicate | 溝通 | They communicate using sounds. |
| whistle | 哨聲 | Each dolphin has a unique whistle. |
| signature | 標誌性的 | It is their signature whistle. |
| echolocation | 回聲定位 | Dolphins use echolocation to navigate. |
| navigate | 導航 | They can navigate in dark water. |
| echo | 回聲 | The echo bounces back from objects. |
| murk | 幽暗的 | The water was murky and hard to see through. |
| habitat | 棲息地 | We must protect their ocean habitats. |
| leap | 跳躍 | The dolphin leaped out of the water. |
Questions
1. (Main Idea) What is the main idea of this passage?
- (A) Dolphins are the smartest animals in the ocean.
- (B) Dolphins communicate through sounds, body language, and echolocation.
- (C) Echolocation is the most important ability of dolphins.
- (D) Dolphins and whales communicate in the same way.
2. (Detail) What is a “signature whistle”?
- (A) A sound dolphins make when they are angry
- (B) A unique whistle that works like a dolphin’s name
- (C) A whistle that all dolphins share
- (D) A sound made by scientists to call dolphins
3. (Detail) How do dolphins use echolocation?
- (A) To call their friends
- (B) To show anger
- (C) To find objects by producing clicks and listening to echoes
- (D) To leap out of the water
4. (Comprehension) What does “breaching” mean in this passage?
- (A) Swimming slowly
- (B) Leaping out of the water
- (C) Making clicking sounds
- (D) Diving deep underwater
5. (Comprehension) Why is echolocation especially useful in murky water?
- (A) Because dolphins cannot see well in murky water
- (B) Because the water is too cold
- (C) Because there are more fish in murky water
- (D) Because sounds travel faster
6. (Detail) What might a dolphin do to show anger?
- (A) Swim close to another dolphin
- (B) Slap its tail on the water
- (C) Produce a signature whistle
- (D) Close its eyes
7. (Main Idea) What is the last paragraph mainly about?
- (A) How dolphins find food
- (B) Why understanding dolphin communication matters
- (C) The history of dolphin research
- (D) How to protect ocean water
Answer Key — Text 1
- (B) — 整篇圍繞海豚溝通的三種方式：聲音、肢體語言、回聲定位。
- (B) — “Each dolphin has its own unique whistle…which works like a name.”
- (C) — “By producing clicking sounds and listening to the echoes that bounce back, they can determine the size, shape, and distance of objects.”
- (B) — “Leaping out of the water, known as ‘breaching.’”
- (A) — “especially useful in dark or murky water where visibility is poor.”
- (B) — “They may slap their tails on the water to show anger or excitement.”
- (B) — 最後一段說了解海豚溝通有助於保護牠們。
Text 2：The Water Cycle（水循環）
Water is essential for all life on Earth. But have you ever wondered where the water in our rivers, lakes, and oceans comes from? The answer lies in a process called the water cycle, which continuously moves water between the Earth’s surface and the atmosphere.
The water cycle begins with evaporation. When the sun heats up water in oceans, lakes, and rivers, some of the water turns into water vapor, an invisible gas that rises into the air. This process is called evaporation. Plants also release water vapor through their leaves in a process called transpiration.
As the water vapor rises higher into the atmosphere, it cools down and changes back into tiny water droplets. These droplets gather together to form clouds. This step is known as condensation. You can see condensation happening in everyday life when water drops form on the outside of a cold glass.
When the clouds become heavy with water droplets, precipitation occurs. Precipitation is any form of water that falls from the sky, including rain, snow, sleet, and hail. The water that falls on the land may flow into rivers and streams, soak into the ground to become groundwater, or evaporate back into the air, starting the cycle all over again.
The water cycle is a continuous process that has been happening for billions of years. It ensures that water is constantly recycled and distributed across the planet, making life on Earth possible. Without the water cycle, there would be no fresh water to drink, no rain to grow crops, and no rivers to support ecosystems.
Key Vocabulary
| English | Chinese | 例句 |
|---|---|---|
| essential | 必要的 | Water is essential for life. |
| atmosphere | 大氣層 | Water vapor rises into the atmosphere. |
| evaporation | 蒸發 | Evaporation turns water into vapor. |
| vapor | 蒸氣 | Water vapor is invisible. |
| transpiration | 蒸散作用 | Plants release water through transpiration. |
| condensation | 凝結 | Condensation forms clouds. |
| droplet | 水滴 | Tiny water droplets form clouds. |
| precipitation | 降水（雨、雪等） | Rain is a form of precipitation. |
| groundwater | 地下水 | Water soaks into the ground to become groundwater. |
| continuous | 持續的 | The water cycle is a continuous process. |
Questions
1. (Main Idea) What is this passage mainly about?
- (A) Why water is important for drinking
- (B) The process of the water cycle
- (C) How clouds are formed
- (D) Different types of precipitation
2. (Detail) What is the correct order of the water cycle?
- (A) Condensation → Precipitation → Evaporation
- (B) Evaporation → Condensation → Precipitation
- (C) Precipitation → Evaporation → Condensation
- (D) Evaporation → Precipitation → Condensation
3. (Detail) What is transpiration?
- (A) Water falling from clouds
- (B) Water turning into vapor from the sun’s heat
- (C) Plants releasing water vapor through their leaves
- (D) Water soaking into the ground
4. (Comprehension) According to the passage, why can you see water drops on a cold glass?
- (A) Because the glass is leaking
- (B) Because of condensation—water vapor in the air cools and turns into droplets
- (C) Because someone spilled water
- (D) Because the glass is sweating
5. (Detail) Which of the following is NOT mentioned as a form of precipitation?
- (A) Rain
- (B) Snow
- (C) Fog
- (D) Hail
6. (Comprehension) How long has the water cycle been happening?
- (A) One hundred years
- (B) One thousand years
- (C) Millions of years
- (D) Billions of years
7. (Main Idea) What would happen without the water cycle, according to the passage?
- (A) The weather would not change.
- (B) There would be no fresh water, rain, or rivers.
- (C) The ocean would dry up in a week.
- (D) People would drink only juice.
Answer Key — Text 2
- (B) — 整篇介紹水循環的過程。
- (B) — Evaporation → Condensation → Precipitation。
- (C) — “Plants also release water vapor through their leaves in a process called transpiration.”
- (B) — “You can see condensation happening…when water drops form on the outside of a cold glass.”
- (C) — Fog 未被提及（只有 rain, snow, sleet, hail）。
- (D) — “billions of years.”
- (B) — “Without the water cycle, there would be no fresh water to drink, no rain to grow crops, and no rivers to support ecosystems.”
Text 3：Traditional Taiwanese Food（台灣傳統美食）
Taiwan is famous around the world for its delicious food. Taiwanese cuisine is a unique blend of different culinary traditions, including Chinese, Japanese, and indigenous influences. Whether you visit a high-end restaurant or a street food stall, you will find an incredible variety of flavors and dishes to enjoy.
One of the most popular Taiwanese foods is beef noodle soup. This hearty dish consists of tender beef, chewy noodles, and a rich, savory broth. Many restaurants have their own secret recipes that have been passed down through generations. Another beloved dish is braised pork rice, known locally as “lu rou fan.” It features minced pork cooked in soy sauce and spices, served over a bowl of steamed white rice.
Taiwan is also known for its incredible street food culture. Night markets, such as Shilin Night Market and Raohe Night Market, are filled with food vendors selling all kinds of snacks. Some of the most famous night market foods include stinky tofu, oyster omelets, bubble tea, and fried chicken cutlets. Stinky tofu has a very strong smell that some people find unpleasant, but many locals consider it a delicacy.
Bubble tea, also known as boba tea or pearl milk tea, was invented in Taiwan in the 1980s and has since become a global phenomenon. It is made by mixing tea with milk and adding chewy tapioca pearls. Today, you can find bubble tea shops in cities all over the world, from New York to Tokyo.
Taiwanese food is more than just a way to fill your stomach—it is an important part of the culture. Many dishes have deep historical roots and carry the memories and traditions of the people who make them. For both locals and visitors, exploring Taiwanese food is a delicious way to understand the island’s rich heritage.
Key Vocabulary
| English | Chinese | 例句 |
|---|---|---|
| cuisine | 料理 | Taiwanese cuisine is famous worldwide. |
| blend | 融合 | It is a blend of different traditions. |
| culinary | 烹飪的 | She studied culinary arts. |
| indigenous | 原住的 | Indigenous cultures are respected. |
| broth | 高湯 | The broth is rich and savory. |
| vendor | 攤販 | Food vendors sell snacks at the market. |
| delicacy | 美味佳餚 | Stinky tofu is a local delicacy. |
| phenomenon | 現象 | Bubble tea is a global phenomenon. |
| tapioca | 樹薯粉 | The pearls are made of tapioca. |
| heritage | 傳統/文化遺產 | Food is part of Taiwan’s heritage. |
Questions
1. (Main Idea) What is this passage mainly about?
- (A) How to cook Taiwanese food
- (B) The variety and cultural importance of Taiwanese food
- (C) Why bubble tea is the best drink
- (D) The history of night markets
2. (Detail) Which of the following is NOT mentioned as a Taiwanese dish?
- (A) Beef noodle soup
- (B) Sushi
- (C) Braised pork rice
- (D) Oyster omelet
3. (Detail) When was bubble tea invented?
- (A) In the 1970s
- (B) In the 1980s
- (C) In the 1990s
- (D) In the 2000s
4. (Comprehension) What is true about stinky tofu according to the passage?
- (A) Everyone in Taiwan loves it.
- (B) It has a strong smell but is considered a delicacy by many.
- (C) It is only sold in restaurants.
- (D) It was invented in Japan.
5. (Detail) What influences Taiwanese cuisine?
- (A) Only Chinese traditions
- (B) Chinese, Japanese, and indigenous influences
- (C) Only Japanese traditions
- (D) American and European traditions
6. (Comprehension) What does “passed down through generations” mean?
- (A) The recipes are new and modern.
- (B) The recipes have been shared from parents to children over many years.
- (C) The recipes are written in books.
- (D) The recipes are kept secret from everyone.
7. (Main Idea) What does the last paragraph suggest about Taiwanese food?
- (A) It is cheap and fast.
- (B) It is an important part of Taiwan’s culture and history.
- (C) It is becoming less popular.
- (D) It is only for tourists.
Answer Key — Text 3
- (B) — 整篇介紹台灣美食的多樣性和文化重要性。
- (B) — Sushi 未被提及。
- (B) — “invented in Taiwan in the 1980s.”
- (B) — “a very strong smell that some people find unpleasant, but many locals consider it a delicacy.”
- (B) — “Chinese, Japanese, and indigenous influences.”
- (B) — passed down through generations = 代代相傳。
- (B) — “Many dishes have deep historical roots” + “a delicious way to understand the island’s rich heritage.”
Text 4：How to Stay Healthy（如何保持健康）
Staying healthy is something that everyone wants, but it requires consistent effort and good habits. There are several key areas that we should pay attention to in order to maintain a healthy lifestyle.
First, eating a balanced diet is essential. This means consuming a variety of foods from different food groups, including fruits, vegetables, whole grains, lean proteins, and healthy fats. It is important to limit the intake of processed foods, sugary drinks, and excessive amounts of salt. Drinking enough water—at least eight glasses a day—also helps our bodies function properly.
Second, regular exercise is crucial for both physical and mental health. Doctors recommend at least 30 minutes of moderate exercise, such as brisk walking, swimming, or cycling, most days of the week. Exercise helps strengthen the heart, build muscle, improve mood, and reduce stress. Even simple activities like taking the stairs instead of the elevator or walking to school can make a difference.
Third, getting enough sleep is often overlooked but is just as important as diet and exercise. Teenagers need about eight to ten hours of sleep per night. Lack of sleep can lead to poor concentration, weakened immunity, and mood swings. To improve sleep quality, experts suggest going to bed and waking up at the same time every day, avoiding screens before bedtime, and keeping the bedroom cool and dark.
Finally, managing stress is an important part of staying healthy. High levels of stress can affect both the body and the mind. Some effective ways to manage stress include talking to friends or family, practicing deep breathing, listening to music, and making time for hobbies and relaxation.
By developing these healthy habits, we can improve our quality of life and reduce the risk of many diseases. Remember, good health is not achieved overnight—it is the result of daily choices and consistent effort.
Key Vocabulary
| English | Chinese | 例句 |
|---|---|---|
| consistent | 持續的 | Consistent effort is needed. |
| balanced diet | 均衡飲食 | A balanced diet includes various foods. |
| whole grain | 全穀類 | Choose whole grain bread. |
| lean protein | 瘦肉蛋白 | Chicken is a lean protein. |
| intake | 攝取量 | Limit your sugar intake. |
| moderate | 適度的 | Moderate exercise is enough. |
| immunity | 免疫力 | Sleep helps boost immunity. |
| mood swing | 情緒波動 | Lack of sleep causes mood swings. |
| overlook | 忽略 | Sleep is often overlooked. |
| disease | 疾病 | Healthy habits reduce disease risk. |
Questions
1. (Main Idea) What is the main idea of this passage?
- (A) Exercise is the most important part of health.
- (B) There are several key habits for maintaining good health.
- (C) Teenagers do not get enough sleep.
- (D) Processed food should be banned.
2. (Detail) How much sleep do teenagers need per night?
- (A) Six to seven hours
- (B) Seven to eight hours
- (C) Eight to ten hours
- (D) Ten to twelve hours
3. (Detail) Which of the following is NOT mentioned as a way to manage stress?
- (A) Talking to friends
- (B) Practicing deep breathing
- (C) Playing video games
- (D) Making time for hobbies
4. (Comprehension) Why does the author mention “taking the stairs instead of the elevator”?
- (A) To show that elevators are dangerous
- (B) To give an example of simple daily exercise
- (C) To suggest that exercise must be intense
- (D) To complain about lazy people
5. (Detail) How much water does the passage suggest drinking daily?
- (A) Four glasses
- (B) Six glasses
- (C) At least eight glasses
- (D) Ten to twelve glasses
6. (Comprehension) What does “good health is not achieved overnight” mean?
- (A) You can become healthy in one day.
- (B) Health takes time and daily effort to build.
- (C) You should only focus on health at night.
- (D) Health is impossible to achieve.
7. (Main Idea) What is the purpose of this passage?
- (A) To sell health products
- (B) To inform readers about healthy habits
- (C) To compare different diets
- (D) To criticize unhealthy people
Answer Key — Text 4
- (B) — 文章從飲食、運動、睡眠、壓力管理四個方面說明保持健康的方法。
- (C) — “Teenagers need about eight to ten hours of sleep per night.”
- (C) — 打電動未被提及（只有 talking, breathing, listening to music, hobbies）。
- (B) — 用來舉例說明簡單的日常運動也能有幫助。
- (C) — “at least eight glasses a day.”
- (B) — overnight = 一夕之間。這句話表示健康需要長期努力。
- (B) — 提供讀者保持健康的資訊和建議。
Text 5：The History of Basketball（籃球的歷史）
Basketball is one of the most popular sports in the world today, with millions of players and fans across the globe. But did you know that it was invented by a single person just over 130 years ago?
The game of basketball was invented in December 1891 by Dr. James Naismith, a Canadian physical education teacher working at the International YMCA Training School in Springfield, Massachusetts, USA. During the harsh New England winter, Naismith’s students could not exercise outdoors, so he needed to create an indoor game that would keep them active.
Naismith came up with the basic rules of basketball in just two weeks. He nailed two peach baskets to the lower balcony of the gymnasium and used a soccer ball for the game. The objective was simple: throw the ball into the opposing team’s basket. Every time a player scored, the game had to stop because someone had to climb a ladder to retrieve the ball from the basket. Later, the bottoms of the baskets were removed so the ball could fall through.
The game quickly became popular. Within a few years, basketball was being played at YMCAs across the United States and eventually spread to other countries. In 1936, basketball was introduced as an official sport at the Olympic Games in Berlin. Today, professional leagues like the NBA (National Basketball Association) attract players and fans from all over the world.
Basketball has changed significantly since Naismith’s time. The rules have been refined, the equipment has improved, and players have become more skilled and athletic. However, the spirit of the game remains the same: teamwork, sportsmanship, and the joy of competition.
Key Vocabulary
| English | Chinese | 例句 |
|---|---|---|
| invent | 發明 | Basketball was invented in 1891. |
| physical education | 體育 | He was a physical education teacher. |
| harsh | 嚴酷的 | The winter was harsh and cold. |
| objective | 目標 | The objective was to score points. |
| nail | 釘 | He nailed baskets to the wall. |
| peach basket | 桃子籃 | He used peach baskets as hoops. |
| retrieve | 取回 | Someone had to retrieve the ball. |
| official | 正式的 | Basketball became an official Olympic sport. |
| refine | 改進 | The rules have been refined over time. |
| sportsmanship | 運動家精神 | Good sportsmanship is important. |
Questions
1. (Main Idea) What is the main idea of this passage?
- (A) How to play basketball
- (B) The history and development of basketball
- (C) Why basketball is better than soccer
- (D) The life of Dr. James Naismith
2. (Detail) Why did Naismith invent basketball?
- (A) He wanted to become famous.
- (B) He needed an indoor game for his students during winter.
- (C) The school asked him to create a new sport.
- (D) He was bored with other sports.
3. (Detail) When did basketball become an Olympic sport?
- (A) 1891
- (B) 1900
- (C) 1936
- (D) 1950
4. (Comprehension) Why did the game have to stop every time a player scored?
- (A) Because the players needed a rest
- (B) Because someone had to climb a ladder to get the ball from the basket
- (C) Because the referee needed to check the score
- (D) Because the ball was broken
5. (Detail) What was originally used as the basketball hoop?
- (A) A metal ring
- (B) A plastic bucket
- (C) A peach basket
- (D) A wooden box
6. (Comprehension) What does “the spirit of the game remains the same” mean?
- (A) The rules have never changed.
- (B) The core values of teamwork and sportsmanship continue.
- (C) The game is still played with peach baskets.
- (D) Only the same people play basketball.
7. (Main Idea) Which of the following best describes the structure of this passage?
- (A) Problem → Solution
- (B) Chronological order (time sequence)
- (C) Comparison
- (D) Cause and effect
Answer Key — Text 5
- (B) — 整篇按時間順序介紹籃球的歷史和發展。
- (B) — “he needed to create an indoor game that would keep them active” during winter.
- (C) — “In 1936, basketball was introduced as an official sport at the Olympic Games.”
- (B) — “someone had to climb a ladder to retrieve the ball from the basket.”
- (C) — “He nailed two peach baskets to the lower balcony.”
- (B) — 精神不變指的是核心價值（團隊合作、運動家精神、競爭的樂趣）。
- (B) — 1891 → 幾年後 → 1936 → 今天——按時間順序編排。
Section 3：說明文閱讀總複習 Checklist
在進入下一篇 R05 高中閱讀-記敘文 之前，請確認你已經掌握：
- 我能分辨說明文的四種類型（how-to, cause-effect, comparison, problem-solution）
- 我能找出說明文的主題句和支持細節
- 我能利用信號字判斷文章的結構
- 我能回答主旨題、細節題和推論題
- 我能在閱讀後用自己的話總結文章內容
恭喜！
你已經完成五篇說明文的閱讀訓練！接下來難度升級，我們要進入高中層次的閱讀了！
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