all by himself

基本解释

Now he's going to America all by himself.
现在，他自己一个人要到美国去了。
I doubt that he created the degree all by himself.
我怀疑那种他学位造假的说法。揭示一下：两个都是“怀疑”，suspect是肯定——怀疑有什么事，doubt是否定性质疑某件事。
That means Yao attracts a major market all by himself.
这代表着姚明一个人就吸引了一整个市场。

"If Madoff acted alone, it would all end right now. There is no way this kind of operation could have taken place all by himself."
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
The hoplite himself is marked by, first of all, the shield and second of all, as we continue to think about his defensive capacities, he has a certain amount of armor to protect his body.
重装步兵的标志,首先就是盾牌,其次,和我们将要说到的防御力有关,就是士兵的身体有一定程度的护甲保护
耶鲁公开课 - 古希腊历史简介课程节选

All the students left the music room, but my brother stood there all by himself.
NPR: Literature and Lullabies from the 'Axis of Evil'