AllY chromosomes in existence today are descended from a single ancestor's who is thought to have lived about 140,000 years ago.
现在存在的所有 Y 染色体都来自于一个被认为生活在大约14万年前的同一祖先。
2
The default setting is 'Y' for all relational data sources, except ODBC sources.
对于除 ODBC 数据源之外的所有关系数据源，默认的设置是 'Y'。
3
The statement /x/y/* returns all nodes under any node y with the parent x. /x/y[@name='a'] matches all nodes y who have a parent x, and have an attribute called name with the value a.
x/y/* 语句返回父节点为 x 的任何节点 y 下的所有节点。 /x/y[@name='a'] 匹配所有具有父节点 x 且具有名为 name 且值为 a 的属性的节点 y。