it seemed certain that

it seemed certain that it seemed certain that their plane would crash it seemed certain that she would be first ship home It seems/seemed certain that...Byrd now knew that he would . 新概念二43课It seemed certain that the plane would crash是不是主语从句?如 At one point,it seemed certain that their plane would crash. it seemed certain that she would be the first ship home.这句话中 At one point,it seemed certain that their plane would crash It seemed certain that the plane would crash为什么不是certainly呢? it seemed certain that she would be the first ship home.这里的s 请教前辈一个英语问题It seemed certain that she would be the first ship （新概念英语）It seemed certain that she the( ) first ship home.