她太害怕了而不知道怎样回答这个问题 英语怎么说

这样最好：
【she was too nervous to answer this question.】
她太紧张害怕而不知如何回答这个问题

【she was too scared to answer this question.】
她害怕惊呆(恐惧)而不知如何回答这个问题

She is too afraid to answer this question

she was too afraid to answer this question.

我觉得这个害怕应该是紧张的意思
She was so nervous that she couldn't answer this question.

She is too scared to know how to answer this question.
不知道怎么回答用how to answer
too...to 太..而不能...

too to 句型肯定是不合适的。太……而不能，但是题目给的是太…而不知道，不是不会回答，而是太紧张不知道怎么去回答。
所以so^……that 是比较合适的，她很紧张以至于她不知道怎么回答。