Many English teachers think that since they had projection of large screens, the blackboard can disappear from the classroom. They regard projection screen as blackboard, prepare lesson by input material, issue, answer and pictures into computer for all, then click the mouse in the classroom, and present a display of large screen. We all know, in English classroom, the teacher should adjust and develop teaching content according to the student’s reaction, lead students to practice, thus achieve the goal of using English to carry on communication. Moreover, the outstanding writing on the blackboard is not only concise, teachers can also adjust, revise the content of the writing on the blackboard at any time according to the doubt that students put forward. If totally substitute the blackboard with the projection screen, it will influence the consistency that student's vision perceive, make students have difficulties of understanding the teaching material focal point and difficult point of the lesson. The content is rejected transiently on the screen, which also influence students to write the classroom note. The experiment proves, the students whom recording the note on the lesson have septuplicate recall ability of the content than to those that not taking notes. (Jia GuanJie, 1996) So if totally replace the blackboard with the display screen, it will influence the advantage of computer multimedia in helping us solving teaching problem.
