这里注意一点，生命线名称带下划线。

Note that, here, the lifeline name is underlined.

youdao

每一部分都由一根下划线隔开，而不是点。

Every piece is separated by an underscore instead of a dot.

youdao

如果你想要着重突出某个知识点，可以下划线并配上相应的注解。

If you want to note something that stands out, underline and write a corresponding note to go along with it.

youdao