第九单元a讲了哪些重点语法？

本单元的主题是 "Interesting and unusual things" (有趣和不寻常的事情)，围绕这个主题，单元内容主要涉及 被动语态 的学习，特别是含有情态动词的被动语态,以及如何描述生活中的趣闻轶事和发明创造。

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核心语法：被动语态

这是本单元最重要的语法点,也是整个初中阶段的重点和难点。

什么是被动语态？

• 主动语态：表示主语是动作的执行者。
  • People invented the telephone. (人们发明了电话。) -> People 是动作 invent 的发出者。
• 被动语态：表示主语是动作的承受者，即动作是“被”执行的。
  • The telephone was invented by people. (电话是被人们发明的。) -> The telephone 是动作 invent 的承受者。

被动语态的基本构成：

be + 动词的过去分词

• be 动词需要根据时态和主语的人称、数进行变化。
• 动词的过去分词：规则动词通常在词尾加 -ed，不规则动词有其特定形式（如 invent -> invented, see -> seen, do -> done）。

本单元重点：含有情态动词的被动语态

这是被动语态的一个重要应用，用来表达“应该/可以/必须被...”等含义。

结构： 情态动词 + be + 动词的过去分词

情态动词	肯定句	否定句	疑问句
can	The work can be finished soon.	The work cannot/can't be finished soon.	Can the work be finished soon?
may	This book may be taken home.	This book may not be taken home.	May this book be taken home?
must	The room must be cleaned every day.	The room must not/mustn't be cleaned every day.	Must the room be cleaned every day?
should	You should be told the truth.	You should not/shouldn't be told the truth.	Should you be told the truth?

用法小结：

• 肯定句：S + 情态动词 + be + V-ed + (by + O).
• 否定句：S + 情态动词 + not + be + V-ed + (by + O).
• 疑问句：情态动词 + S + be + V-ed + (by + O)?

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核心词汇与短语

重点单词

• invent (v.) 发明
  • invention (n.) 发明物
  • inventor (n.) 发明家
• divide (v.) 分开，划分
  • divide...into... 把...分成...
• heat (v.) 加热 (n.) 热量
• sudden (adj.) 突然的
  • all of a sudden 突然地
• rise (v.) 上升，升起 (过去式 rose，过去分词 risen)
• fall (v.) 落下，下降 (过去式 fell，过去分词 fallen)
• smell (v.) 闻起来 (linking verb) / 有...气味 (n.)
• remain (v.) 保持，仍然是
• notice (v.) 注意到 (n.) 通知，告示
• point (v.) 指，指向 (n.) 点；小数点；观点
• accident (n.) 事故，意外事件
• by mistake 错误地
• lock (v.) 锁上 (n.) 锁
• kitchen (n.) 厨房
• soon (adv.) 不久，很快
• happen (v.) 发生
• bell (n.) 铃，钟
• cookie (n.) 曲奇饼干

重点短语

• by accident = by mistake 偶然地，意外地
• be invented by... 被...发明
• divide...into... 把...分成...
• all of a sudden 突然
• the number of... ...的数量 (作主语时,谓语用单数)
• a number of... 许多，一些 (作主语时,谓语用复数)
• without doubt 毫无疑问
• fall into... 落入...
• in the end = finally = at last 终于
• think of... 想到，考虑
• be covered with... 被...覆盖
• at that moment 在那一刻
• make a mistake 犯错
• look for... 寻找
• pay for... 支付...的费用
• even though = even if 即使，虽然
• take place 发生

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核心句型与交际用语

描述发明和发现

• When was the telephone invented?
  • It was invented in 1876.
• Who was it invented by?
  • It was invented by Alexander Graham Bell.
• What is it used for?
  • It is used for talking to people far away.

谈论事件经过

• What happened?
  • I was walking down the street when it started to rain.
• While she was making the soup, she had an idea.
• By the time I got outside, the bus had already left.

  (这个句子是第八单元的重点,但常与本单元的话题结合)

使用情态动词的被动语态提建议或规定

• This old building should be protected.

  这座古老的建筑应该被保护起来。

• The rules must be followed.

  这些规定必须被遵守。

• Wet umbrellas should be left here.

  湿伞应该放在这里。

  
  （图片来源网络，侵删）

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课文重点内容解析

Section A (2d) 对话

这段对话通过一个真实的故事（微波炉的发明）引出了被动语态。

Boy: Hey, did you know that potato chips were invented by mistake? Girl: Really? How? Boy: Well, in 1853, a chef called George Crum was angry because a customer said his potatoes were not thin enough. So he cut the potatoes really thin, fried them and salted them. To his surprise, the customer loved them. Girl: And did they become popular? Boy: Yes, they did. They were called "Saratoga Chips" and soon became popular all over the world.

核心知识点：

• 被动语态的运用：potato chips were invented, the customer said his potatoes were not thin enough, the customer loved them, They were called "Saratoga Chips"。
• 故事叙述：通过 in 1853, Well, So, To his surprise, Yes, they did 等词语，清晰地讲述了事件的起因、经过和结果。

Section B (2b) 阅读文章

这篇文章讲述了茶叶的意外发明,是被动语态和过去时态的综合运用。

Many people believe that tea was first drunk about 5,000 years ago. It is said that a Chinese ruler called Shen Nong was the first to discover tea as a drink. One day, Shen Nong was boiling drinking water over an open fire. Some leaves from a tea plant fell into the water and remained there for some time. It produced a nice smell. Shen Nong decided to taste the hot mixture. It was quite delicious. And in this way, one of the world's favorite drinks was invented.

核心知识点：

• 被动语态的运用：tea was first drunk, a Chinese ruler called Shen Nong was the first to discover..., `Some leaves from a