【正文】 erted will be dull like a stagnant pool of water with no vitality. So the extroverted and introverted students should be integrated. The size of groupingStudy group are often classified according to the seating arrangement and different grouping forms have different group number. The size of each group should be adopted according to the different characteristics of the classes. For instance, for a listening class, the teacher can organize students in groups with two or five students. For a writing class, two or three students in a group can be better, so their writing can be checked for each other and then be checked by the teacher. For a speaking class, students can be 2, 3 or 4 in a group to make dialogues or perform dialogues (roleplaying). In a word, the size of grouping can be random. Thus, in the process of different activities, students can find their own position in various types of groups, municate with their peers and plete their task.The quantity of a group should not be fixed, but should be attached much attention. Piaget points out that the quality and quantity of social interaction accepted by children will pay tremendous impact on their own pace of growth and development. “Besides, the teacher should also pay attention to the group size, which we believe should be from 4 to 6 ideally”(Wang Qiang, 2000: 42). The activities of Cooperative Learning Activities should be designed to help to apply what students have learntIn ELT, the teacher can kindle students’ interest on study and arouse their enthusiasm and initiative on participating in activities, intensifying the training and practice of language to foster students’ logical language ability and municative ability by means of designing activities skillfully.However, when designing activities, two points should be paid attention by the teacher. One is the activities designed to lead students to achieve the municative goal by using English. The other is the topic chosen and activities designed should help students apply what they have learnt ( Yang Suling, 1995).The New Curriculum also makes demands that under the tutor of the teacher, students can achieve learning goal by experience, practice, participation and cooperation. The process of language learning is also thought to be the process of language practice. In high school, the teacher often designs activities to relate to applying what students have learnt. For instance, in NESGC Book1, the students learned the Tang Shan earthquake to know what would happen before an earthquake and what to do during an earthquake, so they will be calmer in the face of natural disaster. Activities should be designed to help to stimulate students’ interest in studyHenning (1983) conjectures that successful SLA may be dependent on the interests that a language learner brings to the learning situation. , an English linguist, asserts that the matter of interest is a matter of prime importance in English teaching as well as the premise to make English easy to learn (Wang Xiangmei, 2001). Spolsky also points out that the motivation of language learning manifest the strong desire and voracious appetite for knowledge, and pulsory learning without interest will destroy the students’ spirit of seeking truth.( as cited in Lin Chongde, 2001). The New Curriculum emphasizes fostering students’ affect on study. The cooperative learning put the study goal to diversify classroom teaching to motivate the students’ interest on study.The effective cooperative learning es from actual activities designed by the teacher that is attractive and interesting. Because the students’ learning approaches usually rely on interests, curiosities and motivations. Thus, the activities designed in accordance with students’ interests in study can in a large scale help to arouse the interest of those students who used to have less motivation to English learning. The roles of the teacher in the activitiesIn the teaching and learning activities, the role of the teacher is considered to be an important ponent of efficient classroom management. However, as Richards and Rodgers point out, the teacher’s roles are related ultimately to assumptions about language and language learning at the level of approach (1986). Teacher’s roles are regarded as part of the design of an approach. In the cooperative learning methodology in English teaching in high school, the role of the teacher is a factor that should be taken into consideration. Harmer defines the teacher’s roles as controller, assessor, organizer, prompter, participant and resourceprovider( see Wang Qiang, 2000). It is somewhat the same as the teacher’s roles in cooperative learning activities.Before the activities, the teacher plays the first role as a planner, who plans what to teach, how to teach, and what result to achieve in the lesson planning, especially plans what cooperative activities to design and how the activities to go smoothly.The teacher acts as the initiator of activities, so the teacher should explain what group forms students can use, the requirements for them in the activities and some notes in cooperative learning. The following explanation of the task shows this role:The whole class is divided into 5 groups and there are 10 members in each group. Five minutes of the beginning of each class, one student of a group is required to make a small presentation. Five English classes each week, so five students from five groups. You can choose various topics to do the performance such as the news from home and abroad or our school, a story, a wonderful passage or even personal feeling about life or study…. What needs to be noticed is that each member in the group should have a chance to participate the preclass activity. You should supervise each other in a group. We will see which group has done the best performance.Therefore, the task can be clearly defined. The teacher as the initiator creates some clear rubrics (tips) at the be