the 1980s 和 the 1980's 哪个对为什么有的题目把两个答案都作为选项同时出现在同一道题中呢？

the late 1980s和the early in the 19th 和in the 1980's in the 1980s,in the 1980's和in 1980s的区别 in the 1980s和in the 1980's是不是都对的?有差别马? 是in the 1980's还是in 1980's好像1980's和1980s是一样的?1980s和1980's是一样哒 兄弟们 in 1980/in 1980s / in the 1980 / in the 1980s / in the 1980's/in the 1980' 两个英语短语请问 in the 1980s 和 in the 1980's 有什么区别呀? ----when were the fossils found?---( ) A At the 1980s B In the 1980s C On 1980,s D In the 1980,s到底那个答案对.好像B和D都是年代的表达! In 1980s和In the 1980s有什么区别 during the 1980s and 1990s 这句话中,1990s前面要不要加the?加和不加有区别吗 是in1980s还是in the 1980s in the 1980s 是什么时候? in the 1980s是指哪几年 in the early 1980s的意思 in the late 1980's怎么翻译 in 1980's 与 in the 1980's的区别 in the 1980s 中的s发声吗? from the 1980s和in the 1980s有什么区别?做作业时老是分不清楚,什么时候用什么呢?