本單元的話題是“發明”，涉及科普知識與技術等內容，是學生最感興趣的話題之一。寫作體裁多為說明文，寫好這類文章一定要抓住事物的特徵、功能和用途。
寫作此類話題作文的常用表達有：
(1)When was …invented?
(2)It was invented…
(3)They are used for…
【典型例題】
計算機在我們的生活、工作中的作用越來越大，你知道計算機的'起源與發展嗎?請結合計算機的發明時間(1946年)、外形、用途等方面，談一下它的發展變化，並說明你對未來計算機的暢想。
【優秀範文】
Computers are becoming more and more important in our daily life. Do you know when the computer was invented?
The computer was invented in 1946. At that time, it was huge. With the development of science and technology, the computer has grown smaller. Now there are many kinds of computers, such as personal computers and laptops. The computer is a very useful tool in our life. For example, it can send some messages to foreign friends by email. What’s more, it can share information with others through the World Wide Web. We can also listen to music or play the game on computers. It makes us relax.
It’s hard to imagine what our life would be like without computers. I think computers will be more convenient and they are going to change our life completely in the near future.
