1.在It was an exciting moment for these football fans this year,when for the first time in years their team won the World Cup中,an exciting moment 是定语从句中的先行词,when是关系副词.
2.在Jackey Chan,for whom life had once been very hard,is cuccessful now中,Jackey Chan是先行词,whom是关系代词
3.在The article shows the reason why people think some colors are warm and others are cool中,the reason 是先行词,why是定语从句中的关系副词.