当没有人和你在一起时，你就是独自一人。

There was no one with you at that time , then you are alone.

youdao

可她始终认为自己就是这个柜子的主人。每当独自一人在房子里打开它的时候，心里总有一股兴奋的感觉，就像小孩子一样。

Still, she always thought of it as hers, and, when alone in the house, she opened it, she experienced a flush of childish excitement.

youdao