请问in the 1840s与since the year 1840有什么区别?

请问in the 1840s与since the year 1840有什么区别? 1.There have been ten thousand visitors to the exhibition since(its opening)请问since后不是用过去时吗,还有与it's opening的区别 2.The radio made in our factory are better than (those)made in theirs请问that what that one 为何不可? The hear railway station has been in s--- since 2002The hear railway station has been in s--- since 2002 英文中since 可否与 until 连用since the Chinese Exclusion Act was enacted in 1882, America closed the door to Chinese immigrants until 1943. 请问可以这样用吗？不可以的话请帮我改正下可以吗？ 英语翻译democracy has already survived the huge television--led decline in circulation since the 1950s 英语翻译RT还有：popular since the mid 70sintroduces in the mid 80s in the 1960's 与 in the 1960s 区别 There__(be)stories about a monster in Scotland since the 1920s. ever since then与哪个同义 ever since,from then on,in the past,from now on 请问Now read how she felt after being in the hiding place since July 1942. It's ten years since the Littles started to work in China.（改为现在完成时） The Littles__ in China in 1980's 与 in the 1980's的区别 In the 90s 与In 90s 的区别 Darwin’s Critics In the century since he proposed it,Darwin’s theory of evolution by n It's said that the poor man——（lie）in bed since the end of last month the house has been _______ since the 1500s.A.in the family's possession B.of the family's possession C.in possession of the family D.of the possession for the family's in the barber与in the barber's用法区别 I am watching the news every day since the huge earthquake in Japan on Friday.请问这句怎么改