关于英语定语从句的题目,将下列句子转换成含有定语从句的复合句：1.China is a developing count

关于英语定语从句的题目,
将下列句子转换成含有定语从句的复合句：
1.China is a developing country ,with Beijing as its capital.
China is a developing country ,___________________________.
2.The thief,having been caught slipping into the bank,was arrested by the police.
The thief,__________________,was arrested by the police.
3.The school has been set up where a wasteland used to be.
The school has been set up ____________________________.
还有请问,非限制性定语从句中,关系词指人是不是只能用whom,就算介词不提前也是用whom?