这句话为什么用过去完成时?They had then been without sleep for twenty-four hours.

西班牙语提问,请问下面这句话的过去完成时用法Ha sido una gran alegría recibir tu carta.这里为什么用ha 不用he ,yo的过去完成时变位不是he 这句话为什么用过去完成时?They had then been without sleep for twenty-four hours. 这句话不该用过去完成时吗?为什么用过去式?She（ trained ）her dog to do whatever it was asked to do before they went for a trip.作为过去的过去,这里的train为什么不用过去完成时? I would rather they did not hear the news.这句话是虚拟用法 为什么要用过去式...I would rather they did not hear the news.这句话是虚拟用法 为什么要用过去式而不是过去完成时 If there had not been a hard layer of rock beneath the soil 这句话为什么要用过去完成时呢?they would have completed the job in a few hours. She and her family hid away for nearly five years before they were discovered为什么不用过去完成时这句话不是过去的过去吗? “Why did you choose your diary and old letters her father asked her.这句话变成间接引语：用过去完成时是对的,为什么可以用一般过去时?这句话本身是一般过去时变成间接引语应该用过去完成时,为什么 为什么说：Where have they been?我知道这是过去完成时,但是为什么不是Where have been they? Ha ha ha I laughed three times!这句话中文说的是什么? 关于 occur的问题It never occurred to me that I would meet my middle school teacher .为什么这句话不用现在完成时或者过去完成时 ?关于occur 什么时候用现在完成时 什么时候用过去完成时? if there had not been a hard layer of rock beneath the soil,they would have completed the job in a few hours.这句话为什么要用过去完成时呢?为什么不用一般过去式呢?改成这样 if there were not a hard layer of rock beneath the 划线的这句话中c(HA) 西班牙语语法,这句话开头为什么要用sese ha negado en redondo a aceptar.他断然地拒绝接受.se这里是自复还是无人称句?直接说ello.ha negado en redondo a aceptar可以吗 Jim's father mended the car.It was broken 怎样用过去完成时把这两句话连成一句话?请注意看要求：用过去完成时把两句话连成一句话！ He had often dreamed of retiring in England and had planned to settle down in the country.这句话中为什么前面用了过去完成时,后面也用 in order that the music industry can develop healthily,we had better ban free music downloads.这句话中的had为什么用过去完成时, thanks to the hard work of the rescue team ,the 13workerd who had been trapped in the mine were saved 这句话为什么要用过去完成时啊 he began to cook after I arrived home这句话最好用过去完成时吧?