原文
Travel can be very beneficial to young people in many ways and therefore gap years, where students travel abroad for a time before embarking upon a career, can be very useful for people as they grow up.
如上,有点不懂为什么可以用where 引导出gap years 的non-defining clause,请问为什么不是用when,而如果要用when去改写句子该如何呢?
在网络上都查不到,麻烦各位大大了。