Finding the Main Idea 閱讀：找出主旨
基礎Main idea 是整段最想講的東西——通常在 topic sentence，其他句子是支持細節。
- Main idea = 整段最想講的東西，一句講完就得
- Topic sentence 多數在段首；Unfortunately / However 這些轉折詞後面好重要
- Details 是支持證據：over 400 million years、500 species 這些數字不是主旨
文體小知識：Find the one sentence that rules the paragraph.
§課文原文 Passage
1Sharks have lived in the oceans for over 400 million years, which means they are older than the dinosaurs. There are more than 500 different species, and they live in every ocean in the world. Some sharks are longer than a bus, while others are smaller than your school ruler. Most sharks are harmless to humans because they eat fish, seals and squid. Only about 10 species are dangerous, and attacks are very rare.
2Unfortunately, people kill millions of sharks every year for their fins. Fishermen cut off the fins and throw the sharks back into the sea. This has caused many populations to drop, and some species may disappear completely. Scientists warn that losing sharks will damage the whole ocean ecosystem, because sharks keep the number of smaller fish under control. Without them, the balance of nature will be destroyed.
3The good news is that everyone can help. We can refuse to eat shark fin soup at banquets and weddings. We can support the shops and restaurants that protect sea life. Several countries have already banned shark fishing in their waters, and Hong Kong has joined an international agreement to protect shark species too. We should protect sharks because they are important for the ocean ecosystem, and a healthy ocean is important for us all.
§逐句中文翻譯 Sentence-by-sentence translation
Sharks have lived in the oceans for over 400 million years, which means they are older than the dinosaurs.
鯊魚在海洋裡生活了超過四億年，即是牠們比恐龍還古老。
There are more than 500 different species, and they live in every ocean in the world.
鯊魚有超過五百個品種，在全世界每個海洋都找到牠們。
Some sharks are longer than a bus, while others are smaller than your school ruler.
有些鯊魚比一架巴士還長，有些就比你的學校間尺還小。
Most sharks are harmless to humans because they eat fish, seals and squid.
大部分鯊魚對人類無害，因為牠們吃魚、海豹同魷魚。
Only about 10 species are dangerous, and attacks are very rare.
只有大約十個品種是危險的，而且襲擊事件非常罕見。
Unfortunately, people kill millions of sharks every year for their fins.
可惜的是，人類每年為了魚翅殺死幾百萬條鯊魚。
Fishermen cut off the fins and throw the sharks back into the sea.
漁民割了魚鰭，就把鯊魚丟回海裡。
This has caused many populations to drop, and some species may disappear completely.
這個情況令很多族群數量下跌，有些品種還可能完全消失。
Scientists warn that losing sharks will damage the whole ocean ecosystem, because sharks keep the number of smaller fish under control.
科學家警告，失去鯊魚會破壞整個海洋生態系統，因為鯊魚控制住小魚的數量。
Without them, the balance of nature will be destroyed.
沒有了牠們，大自然的平衡就會被摧毀。
The good news is that everyone can help.
好消息是，人人都可以出一分力。
We can refuse to eat shark fin soup at banquets and weddings.
我們可以在宴會同婚禮上拒絕吃魚翅。
We can support the shops and restaurants that protect sea life.
我們可以支持一些保護海洋生物的商舖同餐廳。
Several countries have already banned shark fishing in their waters, and Hong Kong has joined an international agreement to protect shark species too.
有幾個國家已經禁止在自己水域捕鯊，香港亦加入了保護鯊魚品種的國際協議。
We should protect sharks because they are important for the ocean ecosystem, and a healthy ocean is important for us all.
我們應該保護鯊魚，因為牠們對海洋生態很重要，而健康的海洋對我們所有人都很重要。
1重點摘要 Summary
Main idea 是整段最想講的東西——通常在 topic sentence，其他句子是支持細節。
2生字卡 Vocabulary
文章主要訊息。
開頭那句。
支持主旨的事實。
證明主旨。
短版。
幾句組成一段。
閱讀文章。
重要的字。
3逐步講解 Steps
- 讀首句主題句多數在段首：P0 第一句 Sharks have lived in the oceans for over 400 million years——立刻知道整段在講鯊魚歷史悠久。段首句不一定第一句：有時例子之後先亮主旨——所以讀埋段尾先好落判斷。
- 找關鍵字重複出現的字就是線索：sharks、ocean、species 不斷出現——主旨一定圍著這幾個字轉。字數比例都是線索：哪個話題佔最多句，主旨就偏那邊——不妨數一數 sharks 出現了多少次。
- 歸納每段用一句講完：P1 = 鯊魚因為魚翅給人大量捕殺。寫 summary 時刪走數字，留回立場。自己先講一次再對選項：『這段是講……』——你講得出的，先算你歸納到的主旨。
- 分主旨細節數字是細節不是主旨：over 400 million years、500 species、only about 10 species dangerous——這些支持住 'Most sharks are harmless' 這個主旨。
- 轉折詞Unfortunately / However 後面好重要：Unfortunately, people kill millions of sharks for their fins——段的立場好大機會在轉折詞後面。轉折詞仲有 In fact / Actually——事實修正訊號：作者講完一般講法，跟住糾正——真意多數在後面。
- 雨傘測試主旨要蓋住整段：'Sharks are old' 太窄；'The ocean is important' 太闊。對的是：We should protect sharks because they keep the ocean healthy.雨傘測試實操：把選項放進 The passage tells us that… 讀一次——蓋到全篇、不會太闊太窄的先選。
- 段落功能三段結構：P0 鯊魚無害（破誤解）→ P1 它們有危險（問題）→ P2 我們可以點幫（解決）。明白結構，主旨自然浮現。留意題目問一段定全文：main idea of paragraph 2 只看該段；the passage 就要蓋住全文——範圍錯，答案實錯。
4圖解 Diagrams
5例題示範 Example
根據鯊魚課文，第二段（人類獵殺鯊魚那段）的 main idea 是什麼？用一句完整英文講出來。
- 第一步：讀段首句——Unfortunately, people kill millions of sharks every year for their fins.
- 第二步：圈出重複關鍵字——sharks、kill、drop、disappear。
- 第三步：檢查其他句子是不是支持第一句——數量跌、物種消失，全部是獵殺的後果。
- 第四步：做雨傘測試——你選的主旨要蓋住段內所有 details。
- 第五步：用完整句作答——The main idea is that…
- 答案：The main idea is that people kill millions of sharks for their fins, and this is pushing many species towards extinction. 段首 Unfortunately… 這句就是 topic sentence；之後的句子（populations drop、species may disappear）全部是 details，用來支持它。答 main idea 題一句講完就得，不用抄細節數字。
6常見錯誤 Mistakes
78 題快測 Quick check
Q1Which sentence is the main idea of paragraph 1?
Q2Where is the topic sentence?
Q3What supports the main idea?
Q4What is a short version called?
Q5What is a block of text called?
Q6What is the main idea?
Q7How many shark species are dangerous?
Q8What should we do?
8重點回顧 Recap
- Main idea = 整段最想講的東西，一句講完就得
- Topic sentence 多數在段首；Unfortunately / However 這些轉折詞後面好重要
- Details 是支持證據：over 400 million years、500 species 這些數字不是主旨
- 雨傘測試：主旨要蓋住段內所有細節，太窄太闊都錯
- 課文立場：鯊魚維持海洋生態平衡——拒吃魚翅、refuse shark fin soup