am的过去式和过去分词是什么

　　例句：

　　I was aware that she was trembling.

　　我察觉到她在发抖。

　　He was rowing for all he was worth.

　　他在拼命地划船。

　　It was a Monday, so she was at home.

　　那是个星期一，所以她在家。

　　What've you been up to?

　　你一直在搞什么名堂？

　　You've been very kind.

　　你真是体贴入微。

　　Progress has been particularly disappointing.

　　进展一直格外令人失望。