Great changes have taken place since you left. 宾语从句的时态的用法则是:当主句是一般现在时时,从句的时态可根据从句的时间状语来任意选择;当主句是过去时时,从句的时态则只能用过去时态的某一种,但从句为客观真理时只能用一般现在时。如: She says (that) she ha...