1．It was a time when the Chinese people were divided geographically.
2．Emperor Qinshihuang united the seven major states into one unified country where the Chinese writing system began to develop in one direction.
3．There are many reasons why this has been possible, but one of the main factors has been the Chinese writing system.
4．These were animal bones and shells on which symbols were carved by ancient Chinese people.
5．It was in 1952 and Mandela was the black lawyer to whom I went for advice.
[我的发现]
(1)关系副词when在定语从句中作时间状语(如句1)；关系副词where在定语从句中作地点状语(如句2)；关系副词why在定语从句中作原因状语(如句3)。
(2)在“介词＋which/whom”引导的定语从句中，which用于指代物(如句4)；whom用于指代人(如句5)。
