帮帮忙中译英（请不要用软件翻译，谢谢）。翻译的词不要太难 就4句，谢谢
1.他们可能到长沙了，是吗？2.我爸说他几年前（a few years before)到过北京。3.他们告诉我那些孩子可能正在河里游泳。4.你爸妈肯定退休了，是吗？
参考答案:They might have arrived Changsha, haven't they?
My father said he was in Beijing a few years ago.
They told me that the children might be swimming in the river.
Your parents must have retired, haven't they?