皮特是在1949年6月8号由约翰逊机长领导的那场空战中牺牲的吗?
这是一个强调句的问句形式.
It was at the air battle on June 8,1949 which was led by Captain Johnson that Peter lost his life.
=Peter lost his life at the air battle on June 8,1949 which was led by Captain Johnson
on June 8,1949 介词短语作定语, which was led by Captain Johnson定语从句 两者都修饰 battle