He was doing it all by himself.

全都是他独自一个人干的。

《柯林斯英汉双解大词典》

I painted the room all by myself.

我独自一人粉刷了屋子。

《牛津词典》

He lives all by himself.

他独自一人生活。

《牛津词典》

I ran so far so fast that pretty soonI was all by myself, which was a bad thing.

VOA: standard.other

Maybe there is no music, so it's just kind of dancing in the middle of a cookie sheet all by himself.

可能会没有音乐，也许只是在众多饼干人中间,单纯地跳舞。

哈佛公开课 - 计算机科学课程节选

It's a... I'd hate to learn all by, when I was a little kid, when I learned, but...

我小的时候很讨厌学，我学的时候…

享受冲浪 - SpeakingMax英语口语达人

The rest of the pieces, all by black artists, were added by the museum.

FORBES: Magazine Article

All the students left the music room, but my brother stood there all by himself.

NPR: Literature and Lullabies from the 'Axis of Evil'

However, only 39% say that stricter gun controls would reduce gun violence all by themselves.

CNN: Pushback on Obama's plan to stem gun violence