1.Group members were able to join group and quit group independently. Besides, members were able to switch in the tree .
成员可以独立地加入组和退出组，并在组播树中进行切换。
2.Penenberg has shown that once enough people join a social network, a viral loop starts in which everyone else wants to join group.
潘恩伯格曾经证明一旦足够的人加入一个社会网络，一个病毒循环（viralloop）开始，在这个循环中不停地会有人加入这个群体。
3.Users can exchange messages privately, similar to e-mail, or join group conversations.
用户们能够秘密地交换信息，类似邮件，或者联机交谈。
4.We will have one or two times per week, regular meetings for members to join group activities.
我们将有两次每周定期举行会议，委员加入小组活动的变径。
5.In 1990, it join group calisthenics of opening ceremony in the 11th Asia Sports Game, was renowned at home &abroad.
1990年参加了第11届亚运会开幕式大型团体操表演，驰誉中外。
6.Bill and Lucy , you can join Group 2.
比儿和露西，你们可以参加第2组。