翻译以下三句句子

1. 9.11恐怖袭击已被记作是美国历史上的一大耻辱（用remember和shame改写)
The Terrorist attack on 11th September was remembered as a great shame in America's/American history.
注意被动的使用，被记作

2.通常来说，钢琴家都在早年接受专业训练（用age改写）
Generally speaking,the pianists began to have professional training at their early age.
注意，age 要用 at 作搭配

3.在解决了一个又一个问题后，科学家们终于在实验中取得了重大成功（用master改写）
After sovling problems again and again,the scientists eventually master great/significant success.
注意，after 后加短语，不加句子
一般，master 作动词常表示掌握，比如master a foreign language
向此句这样的用法较少

尽力回答了，希望答案能满足您的要求。^0^

9.11 terror attack has been remembered as a shame in American history.

Generally speaking, pianists are trained in the young age.

Maters finally succeed in the experiment after resolving the problems on after another.