《When was it invented?》SectionB PPT课件下载(第3课时)

人教版九年级英语上册《When was it invented?》SectionB PPT课件下载(第3课时)，共37页。

Objectives

To summarize the passive voice of the past tense.

To think about your problem and think of the new invention to solve your problem.

To write a passage to describe your invention. 

Revision

一般过去时被动语态

一般过去时的被动语态表示过去某一时刻发生的被动性动作, 其基本结构为：

主语 was / were 过去分词 by …

►The teacher was visited by them two years ago. 

他们两年前看过这位老师。

主动变被动解题步骤:

1. 找宾语 ——即动作的承受者

2. 判断宾语的单复数 ——即be动词的单复数

3. 判断动词的时态 ——即be动词的时态

4. 修改谓语的时态 ——即原句动词改为过去分词

5. 修改原句的主语 ——即by 主语/ 宾语

Warming up

Inventions are everywhere in our life.

Imagine you are a business person. Write a description of your new invention. Try to sell the invention to the class.

This special pen was invented by Liu Jie.

It has three colors and is used for…

Sample writing

This special pen was invented by Liu Jie. It has three colors and is used for taking notes quickly. It is very useful if you have a lot to write down. The pen comes with a microchip that can store a list of common words that you will use. You can program the words you will use often into the microchip’s memory, then assign a short form to each word. When you are writing, you just need to write the short forms with the pen, press a button on the pen and the short forms will change into the actual words. The microchip can contain up to 50 words and you can make changes to the list of words whenever you need to.

Self check

Complete the passage with the correct form of the words in the box.

invent    doubt      mention website     all of a sudden

It is often difficult to decide on the inventor of certain inventions. This is because sometimes a few people may ______ things which are nearly the same. It’s hard to tell who came up with the idea first. 

Some inventions can also lead to other inventions ______________. So some people _________ whether the inventor came up with the idea himself or herself. They think that the inventor used someone else’s idea to create his or her invention. That is why books or ________ usually _________ more than one inventor when giving information about inventions.

Rewrite these sentences using the passive voice.

1. Someone stole my watch.

2. They used five eggs to make this big cake.

3. When did they invent the personal computer?

4. They asked us not to run in the hallway.

5. Someone took the video back to the store.

Homework

Write an article about your favourite invention.

Do some exercises about passive voice.

Preview the new words in the next unit.

… … …

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