1986年算1980s 还是1990s

1986年算1980s 还是1990s 1986是属于1990s还是属于1980s?谢谢 “八十年代”英语中是1980s还是1980’s? in 1990s还是in the 1990s in the 1990s'还是in the 1990's 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 1980s中的s怎么发音?我是说发/s/还是/z/. 是in1980s还是in the 1980s class's还是class’ Dennis's 还是Dennis' this怎么读是类s 还是地s 大S漂亮还是小S漂亮 大s美还是小s美? It's danger 还是 It's dangerous cheers的s读z还是s classrooms 的s读 “s” 还是“z” basketballs的s读s还是z it's fun 还是it 's funny