是in1980s还是in the 1980s

是in1980s还是in the 1980s 是in the 1980's还是in 1980's 是in 1980s对还是in the 1980s对? 是in the barber's 还是at barber's “在二十世纪八十年代”,用英语怎么说?是“in the 1980s”还是“in 1980s”? 1）是in 1980s还是in the 1980s 2）The girl in white must be a nurs 在80年代,英语表达法是in 80s 还是 in the 80s 是It's in north of China.还是It's in the north of China in the 1990s'还是in the 1990's 是on the morning of Mother's Day还是in the morning of Mother's in the 1950s 还是in 1950s in early 1990s还是in the early 1900s?