I shall never forget the days _____ I spent in Beijing University, _____ has a great effect on my life. [ ]

A. that; which

B. which; that

C. when; that

D. when; which

一块石头符号化的过程是从什么时候开始的？（）

A.从把石头称为石头就开始，因为它成了一个类别的代表

B.从人把石头做装饰时就开始

C.从人用石头做工具或武器时就开始

D.从人注意到这块石头是就开始