He said it should be by choice.

他说这应该是自愿的。

" I played a part, though not by choice" .

" 我也有责任，虽然我身不由己。"

Why would we do it to ourselves by choice? !

为什么我们会选择这样对自己？！

But he was the first who ever did so by choice, out of principle.

但他确实是第一个自愿这么做的人，这是出于他自己做人的原则而已。

Okay, I'm not here by choice.

我来这里并非自愿。

Don't you dare say I'm in here by choice.

别说什么入狱是我自己的选择。

To refrain means that you stop yourself from doing something by choice.

“To refrain”是指你自愿地阻止自己做某事。

By choice, he has no electricity, no gas, and no indoor plumbing.

他选择不使用电、煤气，也不安装室内管道。

So, no, this is about fairness to the people who are childless by choice, okay?

所以，抱歉，我要对没有孩子的人公平，好么？

Unlike in high school and most of college, by choice. - Where's the opener?

跟在高中和大学时不一样，你们是主动来的。 - 开瓶器在哪里？