To his surprise ,it isn't a mouse's room.

To his surprise ,it isn't a mouse's room.
To his surprise ,it isn't a mouse's room.

To his surprise ,it isn't a mouse's room.
字面翻译：让他吃惊的是,那不是老鼠的房间
这明显是一段文字的部分,要明白全部意思,那也要根据上下文啊,我好像读过,好像是对一个旅馆的评价,旅馆主人认为那影响了他生意,就告他,然后他就这么回答,有反话讽刺的味道.