摘要
Across the whole world, there emerges the 'generation trend' in which the age of puberty declines. The starting age of breast development of Chinese girls in urban areas is only later than African American and Chilean girls; their age of menarche is earlier than that of the girls in most European countries except Greece and Italy and is also slightly earlier than that of white American girls.
Across the whole world, there emerges the ＂generation trend＂ in which the age of puberty declines. The starting age of breast development of Chinese girls in urban areas is only later than African American and Chilean girls; their age of menarche is earlier than that of the girls in most European countries except Greece and Italy and is also slightly earlier than that of white American girls.
