给定一篇英语文章，将其中每个动词的时态更改为过去时，并将每个名词的单数形式更改为复数形式。输出处理后的文章。
原始文章：The cat sits on the mat. He meows to be let outside. Sarah plays the piano every day.
The cats sat on the mats. They meowed to be let outside. Sarah played the pianos every day.