Washington DC 还是 Washington,DC 还是?请告诉我其中逗号句号的标准用法!

Washington DC 还是 Washington,DC 还是?请告诉我其中逗号句号的标准用法! I arrived in washington DC yesterday ,it was very beautiful .I( )to live there.是want 还是wanted Washington DC和Washington有什么区别? Washington和Washington DC什么区别? 华盛顿的英语Washington DC. washington dc 属哪个州 Washington DC中的DC在这里是什么意思? booker washington was a famous Washington D.C中的DC代表什么? Washington,为什么华胜顿后面有DC呢? Washington, 英语翻译In 1996,film director Roland Emmerich destroyed the White House -- on camera.That was for his movie Independence Day, in which space aliens invaded Washington DC 2900 south lake street washington dc 20012 usa甚么意思 washington,DC .taxation with out representation.求翻译 Mr Black went to Washington DC by air last Monday.同义句转换.Mr Black( )( )Washington DC last Monday. Washington.知道Washington是华盛顿的意思,但是在很多地方都是Washington 和 DC一起出现的,不知道有什么不同, George Washington was the first president of the United States. Washington was famous( )the first America presidenta.for b.as