in the 1970s和in the 1970's有区别吗,还有怎么读?这两种说法都可以

in the 1970s；in 1970s；in 1970's；in the 1970's哪个对? in 1970、in the 1970、in the 1970‘s、in the 1970s有什么区别 in the 19th 和in the 1980's in the 1980s,in the 1980's和in 1980s的区别 in 1900s 和 in the 1900s那个对? in 1960's 和in the 1960s的区别 in 1720s和in the 1720s的区别 in the cat,s In the stationary’s in the 1970s=in the 1970's还是=in 1970's in 1970s; in the 1970's ; in the 1970s'.那种对呀, in the 1990s,in the 1990's和in 1990的区别 in the in the 1720's呢? in the 1970s和in 1970s 有什么区别 in 1990 和 in the 1990s的区别 in the 1940's和in the1940s一样吗? in the 1970s和in the 1970's有区别吗,还有怎么读?这两种说法都可以 in 1980/in 1980s / in the 1980 / in the 1980s / in the 1980's/in the 1980'