谈不上特殊的先行词.关键看关系词在从句中做什么成分.如: I want a job where I do little but can earn a lot. Many cases,where people can't speak English well,are the result of education.
没有固定的,关键看做什么成分。就如你说的occasion做先行词,也不一定都用where 如: These occasions, which you often talk about, uauslly happen when people are abroad. 这些你们经常谈到的场合,通常发生在出国的时候。