集体名词单复数情况根据什么选择?如family,class,police等,请举例说明,

family class 强调整体时谓语动词用单数,强调整体中的每个成员时谓语动词用复数,police一般以复数出现
His family is big .
His family are very happy.
My class is a united class.
My class are happy and healthy .
The police are working in the street .