This is one of the happiest days ______ spent in my life.
A:that have ever been
B:that have never been
C:which was ever
D:which we have never
若该校七年级共有男生480人,请估计全年级男生体质健康状况达到“良好”的人数
美国加利福尼亚南部,距东北部的主要市场很远,但农业生产的集约化程度高,其农产品大量销往美国东北部市场,其主要因素是( )