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.

鱼、肉、奶、花生、豆类等食物中含丰富的（　　）

中日友好交往源远流长．如图是唐朝时期曾为中日两国的友好交往做出突出贡献的人物，他是（　　）

若关于x的方程2x－a＝0的解比方程4x＋5＝3x＋6的解大1，求a的值．

选择恰当的词语填入括号中。

维护   维持

①  作为消费者，我们应该用法律____自己的合法权益。

②为了____这个家，妈妈简直操碎了心。