People of different countries and regions different nationalities and cultures have forme

问题补充：

People of different countries and regions, different nationalities and cultures have formed with solidarity an Olympic family, they have deepened understanding and enhanced friendship.

A. when

B. which

C. that

D. in which

答案：

A. when

B. which

C. that

(答案→)D. in which

解析：考查定语从句。句意“不同国家和地区的人，不同国籍和文化，以团结组成奥运大家庭，在那里，他们加深了理解，增进了友谊。”根据逗号可知，是非限制性定语从句，排除that；从句不缺少成分，排除B；逻辑主语是family，指地点，故用in which。故选D。