John had to have his car repaired in a garage because it      seriously.    [ ]

A．damaged                    

B．was being damaged    

C．had damaged                  

D．had been damaged

病原体侵入人体后，仅引起机体发生特异性的免疫应答，而不引起或只引起轻微的组织损伤，临床上不显出任何症状、体征与生化改变，只能通过免疫学检查才能发现。此种表现属于( )

A．显性感染
B．病原体被清除
C．潜伏性感染
D．病原携带状态
E．隐性感染