是的过去式是什么

The system was state of the art.

这一系统是当时最先进的。

It was a time of peak demand for the product.

那是对该产品需求最旺的时期。

Much of the form was not applicable to me.

表格中很多部分不适用于我。

For a long time his death was concealed from her.

他的死瞒了很长时间都没告诉她。

She was not only intelligent but also very musical.

她不仅聪明，而且极具音乐天分。