3.2 Emotion
    If middle school’s students have an active emotion, the students can form great study interest and arouse study motivation. At the beginning of class, lead-in is the important part to arouse passive emotion. Passive emotion can affect language study. The teacher should praise and encourage students to make great progress in study. Some students often complain that English is so difficult, but they always ignore their lazy emotion. In fact, they lack will emotion so that they can not persist finishing their English study all the time. Because of middle school students’ psychology traits, their attention is not stably enough, and their studying purpose is not definitely enough. If they are interested in something they will concentrate on the attention. Therefore, in order to make students’ English achievements get better and better, we should research the interest effects of lead-in in learning and teaching English. So it is important to cultivate students’ good emotion. As teachers, we should encourage students to work hard, help them fix their learning passion voluntarily to achieve study purpose in the process of lead-in.
3.3 Reality
    Since the 1990s, people have begun to lay the emphasis on the using of authentic materials, which are also considered to have played a important part in the success of the communicative language teaching. Nunan (1985), Rivers (1987), Vanpattern (1991) emphasizes the necessary of the authentic materials. Harmer (1991) thinks that only the authentic materials can genuinely improve the students’ listening and speaking skills. The lead-in topic must link to the student’s real life. The teacher should select some practical detils or well-know knowledge aeras linked to the lessons learned, and give their views. The lead-in should not be very difficult, because difficult topic require high level mental processing to communicate meaning and learners. Students will feel it difficult to express themselves and can not build the good interact with teacher. A good lead-in should be based on authentic or naturalistic source material and suit for communication, such students can learn to combine English into real life and use it effectively. If they are familiar with the topic their learning motivation will be easily aroused. So we should follow reality principle.
3.4 Interaction
    The talents of 21st century must have the quality and ability to cooperate with other people, so teachers need to cultivate the spirit of teamwork in middle school. The traditional lead-in methods is the teacher-centered classroom, all the activities in the whole class are controlled by teacher, and students just listen or do something to the order. In this way, students’ motivation can not be inspired and they are just passive receivers. The essence of English learning requires student to listen, speak and read more. Only by practicing more, language can be actually acquired. The teacher in the class acts a guide or supervisor, who must inspire students to participate in lessons, during the interaction time the students should mobilize their enthusiasm. Therefore, a hot learning atmosphere need guided by teachers, also need established by each student together in lead-in.
IV The Methods of Lead-in teaching
    Actually, lead-in is an art. The methods of lead-in in English teaching are perse. According to different typles and contents of every class, teachers should choose diffierent methods. Whatever they chose, the only aims of these methods is to stinulste students’ interest in learning so that students can rebuild self-confidence, fell that English is easy to learn and very interesting. The following methods just give us a general picture, which is prerequisite for us to analize lead-in.
4.1 Traditional Strategies
The first tradition strategies is revision strategies. David Ausubel (1960) who put forward a meaningful learning theory. In his view, to learn meaningfully, students should relate new knowledge to what they have already learned. Revision is connection between the old and new knowledge. Lead-in by revision, giving a familiar terms and knowledge to help student accept the new knowledge quickly, also make them remember the old knowledge. This step will inspire them to review what the student have already acquired, it’s the process of transforming knowledge dan creatively applying it in the coming new situations. The old says is that learn the new things from reviewing. It easy to link the old and new knowledge logically and facilitating the teaching of teachers to carry out step by step by revision strategies. 中学英语课堂导入艺术浅析(3):http://www.youerw.com/yingyu/lunwen_7673.html