课件15张PPT。Unit3 Computers WHO AM I?Reading How to find the topic sentence? Exposition 说明文Topic sentencethinking? How to find it?What is topic sentence? Over time I have been changed quite a lot 1642 The computer began as a calculating machine. 1822 The analytical machine was made by Charles Babbage. 1936 Alan Turing’s universal machine 1940s The computer had grown as large as a room 1960s Family of computers was connected to each other. 1970s PC & laptop were used in offices and homes.Now Computers connect people all over the world together.transistorschipsnetworkWorld Wide WebThesechangesonly became possibleas my memory improvedtubesI have a memory like an elephant. = I have a good memory and will never forget things.APPSince the 1970smanynew applicationshave been foundfor mecommunicationtrade medical operations space rocketsmobile phonerobotsFinanceAPPSupporting details calculating machine analytical machine universal machine PC laptopmemory tubes transistors chips network WWWcommunication finance trade robots space rockets mobile phone medical operations1. Over time I have been changed quite a lot. 2. These changes only became possible as my memory improved. 3. Since the 1970s many new applications have been found for me.historydevelopmentusesmain idea of the textThis text told us the _____ and the _____ of computers , mainly to express its widely _____. Topic sentenceMain ideahistorydevelopmentusesExercises time
