1、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 asa calculating machine.1822The analytical machinewas made by CharlesBabbage.1936 Alan Turings
2、universal machine 1940sThe computer hadgrown as large as aroom 1960s Family of computerswas connected to eachother.1970sPC&laptop were used in offices and homes.NowComputersconnect peopleall over theworld together.transistorschipsnetworkWorld Wide WebThesechangesonly becamepossibleas my memory impro
3、vedtubes I 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 machineanalytical machineuniversal mac
4、hinePClaptopmemorytubestransistorschipsnetworkWWWcommunicationfinancetraderobotsspace rocketsmobile phonemedical operations 1.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 timeHomeworkReading material Find out the topic sentence for each paragraph.Write down the main idea of the text.
