1·For example, if you copy messages, they appear at the bottom of the original lifelines.
例如，如果您拷贝一个消息，它们就会显示在最初生命线的底端。
2·You can even copy lifelines and only a portion of the messages.
您甚至可以拷贝生命线以及这个消息的一部分。
3·Changing the order of lifelines does not change the semantics of the diagram, but it often improves the clarity or aesthetics of the diagram.
变更生命线顺序的操作并不会更改图表的语义，但是它通常会提高图表的清晰度和美学意义。
4·A similar problem would occur with lifelines.
生命线也会出现相同的问题。
5·States or conditions are added to the horizontal lifelines to represent changes in states or conditions over time.
状态或者情况会添加至水平生命线以代表状态或者情况随着时间所发生的变化。