21.Analysts said that sport in general has become a social elevator. 提高人的社会地位

　　22.bold exploration

　　23.need to be developed to meet/satisfy increased demand.

　　24.at a primary stage of development

　　25.transient

　　26.I'm a native of Jiangsu province

　　27.lifetime occasion 人生大事(结婚等)

　　28.The number of A has been on the rise for the past decade.

　　29.choose a happy and easy way to do sth instead of being bound by tradition

　　30.Sun Zhongshan paved the way toward a Chinese utopia, but could only show it on paper.