in 1950 ,in 1950s,in the 1950s,in the 1950's,in 1950's这四个短语都存在么?

in the 1950s还是in 1950s in the 1950s 还是in 1950sin the 1950's 还是 in 1950's in 1950 ,in 1950s,in the 1950s,in the 1950's,in 1950's这四个短语都存在么? 英译中 in the 1950s in the 19th century in 1950s 与in the 1950s有什么区别?in 1950s是表示1950----1959还是1940---1949?in the 1950s呢? in in in in in in in in in in in in in