我断定她已经死了.用英语怎么说？

我断定她已经死了.

I ascertained that she was dead.

ascertained

v. 弄清，确定，查明( ascertain的过去式和过去分词 )；

例句
Once they had ascertained that he was not a spy, they agreed to release him...
一旦确认他并非间谍，他们即同意将他释放。

that

det. 那个，那；pron. 那个，那；conj. 多么，如此…以至，用于某些动词、形容词和名词后，引出各种从句；adv. 不那么，那样；

例句
...expensive make-up that we saw being advertised by a beautiful model...
我们所见的由一位漂亮模特代言的昂贵化妆品

she

pron. 她，它；

例句
Her lover walked out on her after she had aborted their child.
她的情人在她打掉胎儿后甩了她。

was

v. 用来表示某人或某物即主语本身，用来表示某人或某物属于某一群体或有某种性质（ be的过去式 ），在，存在，不受干扰；

例句
There was a terrible sadness in her eyes...
她眼神中流露出深深的悲伤。

dead

adj. 死去的，完全的，无感觉的，呆板的；adv. 完全地，非常，绝对，极度；n. 死者，（死一样的）寂静，极寒时候；

例句
According to police accounts, Mr and Mrs Hunt were found dead on the floor of their kitchen.
据警方称，亨特夫妇被发现死在家里厨房的地板上。