问题
选择题
(2008·山东，26)Occasions are quite rare ________ I have the time to spend a day with my kids.
A．who
B．which
C．why
D．when
答案
答案：D
句意：我很少有机会和我的孩子们一整天都待在一起。先行词为occasions，代入定语从句后为：I have the time to spend a day with my kids on_the_occasions.由此可知关系词在定语从句中作状语，故用关系副词，排除A、B两项；occasion不表原因，排除C项，答案为D。