问题补充：
Our teachers always give us good advice. We should follow .
A. what they say
B. what they said
C. which they say
D. which they said
答案：
A. what they say
B. what they said
C. which they say
D. which they said
解析：考查宾语从句的用法。say是及物动词，要跟宾语what，排除C、D选项；句意是：我们应该按照老师说的来做事。并未强调时间的前后，排除过去时said。故选A。
