Computer mouse The basic computer mouse is an amazingly clever invention with a relatively simple design that allows us to point at things on the computer and it is very productive. Think of all the things you can do with a mouse like selecting text for copying and pasting, drawing, and even scrolling on the page with the newer mice with the wheel. Most of us use the computer mouse daily without stopping to think how it works until it gets dirty and we have to learn how to clean it. We learn to point at thing before we learn to speak, so the mouse is a very natural pointing device. Other computer pointing devices include light pens, graphics tablets and touch screen, but the mouse still our workhorse. How does the mouse work? We have to start at the bottom, so think upside down for now. It all starts with mouse ball. As the mouse ball in the bottom of the mouse rolls over the mouse pad, it presses against and turns two shafts. The shafts are connected to wheels with several small holes in them. The wheels have a pair of small electronic light-emitting devices called light emitting diodes mounted on either side. One LED sends a light beam to the LED on the other side. As the wheels spin and a hole rotates by, the light beam gets through to the LED on the other side. But a moment later the light beam is blocked until the next hole is in place. The LED detects a changing pattern of light, converts the pattern into an electronic signal, and sends the signal to the computer through wires in a cable that goes out the mouse body. This cable is the tail that helps give the mouse its name. The computer interprets the signal to tell it where to position the cursor on the computer screen. 1. Most computer users want to know how the computer mouse works. 2. According to the author, general computer users need not know how the computer mouse was invented. 3. The computer mouse derives its name from the cable that goes out its body, which looks like the tail of a mouse. 4. The key components of a computer mouse are the two LEDs. 5. When an ordinary computer mouse gets dirty, it has to be replaced with a new one. 6. The most durable computer mice on sale are the IBM ones. 7. The optical mouse is superior to the basic one in that the former has no moving parts.
伊丽莎白·泰勒的20句名言(上)
美文欣赏:价值源于善良而非金钱
遵守承诺的重要性The Importance of Keeping Promises
美国50个州州名简称及首府英语怎么说
如何同美国人展开对话
英文简历到底该怎么写呢?(二)
丘吉尔经典名言选录(一)
歌颂母亲的名人名言
美文赏析:书写人生
励志美文:如何成为王者
英语美文:为梦想加油
《暮光之城》中的爱情观The Love Attitude From Twight
丘吉尔经典名言选录(二)
美文赏析:一个人的旅行 解放心灵开拓视野
世界糖尿病日 World Diabetes Day
名人名言(科学经济类)
备考策略解读:英语面试的7个小贴士
想看美剧提高英语?这些错误别再犯了!
励志名言不励志:箴言背后的残酷真相
诗歌赏析:汪国真《热爱生命》
经典诗歌《圣诞前夜》
Hillary Clinton’s concession speech 2016(希拉里败选演说)
美文赏析:让将来的你感谢现在努力的自己
英语励志名言精选
毕业生励志名言集锦
英语美文:改变你生命的四个问题
泰戈尔经典名言汉英对照(下篇)
世界各个国家英文怎么拼?
少女梦 The Young Girls Dream
面试中如何回答“你的缺点是什么”
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |