All language changes over a period of time, for reasons which are imperfectly understood.
All language changes over a period of time, for reasons which are imperfectly understood.
所有语言经过一段时间就要变，其变化的原因是无法完全搞清楚的。
All language changes over a period of time, for reasons which are imperfectly understood.
所有语言经过一段时间就要变，其变化的原因是无法完全搞清楚的。