a.Give the definition of "Group" in your own words.

A GROUP is formed when people work together with the same goal. And to make the group work in order, there will be norms.

b.Discribe the detailed characterictics of the groups.

THERE are ten charateristics of a group, including interdependence (members are mutual dependent), common goal(members have a same goal), group personality (a collective identity of the group), commitment(the desire of group members to work together to complete their task), cohesiveness(the attraction that group members feel), group conflict(different ideas between members) , social facilitation(The tendency for a person to release energy), gender differences(members' gender can be different), group size( the number of members) and norms(the expected and shared ways in which group members behave).

 C.How to make the group members get into a positive participation during the group communication?

GIVE them enough imformation of work and organize gruop discussions regularly. While, in every discussion, the leader should set a goal and a time limit.