20世纪90年代以来，世界多极化趋势加强指的是（    ）

    Humans like to live and work in groups. Language is the “cement(胶合剂)”____holds these groups together. Language is part of culture. Culture, in this sense,____ (mean) all those customs, skills, and attitudes that are part of the behavior of a ____ (particularly) group. What you think ____ what you want in life are all affected by the culture of the group in which you ____( raise). Groups of people live in different ways. They may have different skills, organizations, and art forms. Their family life may be completely different from yours.

    Human beings are inventive animals. They can decide to change their cultures in order to meet various ____(situation). Of all living things, human beings are the ____(clever). They can choose ____(live) in many environments and in a wide variety of ways. Only human beings can choose where and how they want to live and then improve the physical environment to help ____(they)realize these choices.

    Acquiring the wisdom to make wise choices ____ (be)the lasting challenge of being human.

每年的12月5日是“国际志愿者日”，2016年国际志愿者日前后，我国数百万志愿者广泛开展丰富多彩的志愿服务活动。参加志愿服务活动（    ）

①是服务社会的好形式               ②是承担社会责任的表现

③能更好地实现自身价值           ④有利于养成亲社会的行为