单选题
Culture (文化) unchangingly molds (影响) human biology. Culture encourages certain activities, discourages others, and sets standards of physical health and attractiveness (吸引力). Sports activity, which is influenced by culture, helps build phenotype (具有共同类型的一类有机物). American girls are encouraged to pursue and so, they do well in -competitive track and field, swimming, and diving. Brazilian girls are encouraged to avoid public activities. In Brazil fewer females swim, drive, and run than is the case in America. Culture standards of attractiveness also affect athletic activities. Americans run or swim not just to compete but to keep trim (漂亮的) and fit (健康的). Brazil' s beauty standards accept more fat, especially in female buttocks and hips. Years of swimming mold an enlarged upper torso, a massive neck, and powerful shoulders and back. Successful women swimmers tend to be big, strong, hard and bulky, but Brazilian culture says that women should be soft. A Brazilian beauty should have big hips and buttocks rather than big shoulders. So Brazil seldom sends female swimmers or runners to the Olympics. The countries that produce successful female swimmers are the United States, Germany, and Russia or any other one but not Latin countries including Brazil.