A. A combination of two or more interacting and interdependent individuals in order to achieve a specific goal.

B. There are ten different characteristics. The first characteristic is interdependence, which means that members depend on each other. The second characteristic is the common goal, which is to unite people into the driving force of the group. The third characteristic is group personality, which represents people's collective identity when they gather in the group. The fourth feature is commitment, which is the desire of group members to work together to complete the task and make the whole group satisfied. The fifth is cohesiveness, the desire and determination of group members to unite. The sixth is group conflict, which refers to the hostility between groups and mutual interference in each other's activities, but it is not always harmful. The seventh is social promotion, which refers to the phenomenon that others are present or act together with others, resulting in the improvement of behavior efficiency. The eighth is gender difference, which refers to the different attitudes and behaviors of men and women in the group. The ninth is the group size, which refers to the number of people in a group. The tenth is norms, which means that every member must abide by the agreed standards of thought and behavior.

C.The first questions should be relevant, express your own questions clearly, and encourage people to come up with different ideas.