Their two children were immigrants to Northern Ireland from Pennsylvania...是什么意思？

Their two children were immigrants to Northern Ireland from Pennsylvania...

他们的两个孩子是从宾夕法尼亚州移民到北爱尔兰的。

their

pron. 他（她，它）们的，在提及性别不详的人时，用以代替 him 或 her；

例句
Their permissiveness toward their children reflects the wild abandon of their own lives.
他们对孩子的放任折射出他们自身生活的放浪形骸。

two

n. 两个，两个东西，两点钟，一对；adj. 两个的，我

例句
He has been absent from his desk for two weeks...
他已经有两个星期没有坐在办公桌前了。

children

n. 孩子们(child的复数)，儿童，膝下，孥；

例句
Their permissiveness toward their children reflects the wild abandon of their own lives.
他们对孩子的放任折射出他们自身生活的放浪形骸。

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

immigrants

n. 移民( immigrant的名词复数 )；

例句
Large numbers of immigrants flooded into the area...
大量移民涌入这个地区。

to

prep. 向，朝着，到，关于，属于；adv. 朝一个方向的，到某种状态，关闭；

例句
I suggest you leave it to an expert...
我建议你把它留给专家来解决。

northern

adj. 北方的，北部的，来自北方的，北风；

例句
What really sets Mr Thaksin apart is that he comes from northern Thailand...
他信先生真正与众不同之处是他来自泰国北部。

Ireland

n. 爱尔兰（岛）；

例句
Most areas suffered more rain than usual, with Northern Ireland getting double the average for the month.
大部分地区降雨超过通常水平，北爱尔兰地区本月的降水量则为平均值的两倍。

from

prep. （表示时间）从…，（表示原因）因为，（表示来源）来自…，（表示分离）与…分离[隔开]；

例句
...an abortive attempt to prevent the current President from taking office.
企图阻止现任总统连任的失败尝试

Pennsylvania

n. 宾夕法尼亚州（美国州名）；

例句
A military parade marched slowly and solemnly down Pennsylvania Avenue.
阅兵队列沿宾夕法尼亚大道缓慢而庄严地行进。