他们家世世代代都是公侯.用英语怎么说？

他们家世世代代都是公侯.

Their family has had dukes and marquises for many generations.

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。

family

n. 家庭，家族，孩子，祖先；adj. 家庭的，一家所有的，属于家庭的，适合全家人的；

例句
Almost like an accident of nature, this family has produced more talent than seems possible.
就像是天缘巧合，这个家族不可思议地人才辈出。

has

v. 有( have的第三人称单数 )，（亲属关系中）接受，拿，买到；

例句
...the operation a patient has had.
病人做过的手术

had

v. 有（ have的过去式和过去分词 ），（亲属关系中）接受，拿，买到；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

dukes

n. 公爵( duke的名词复数 )，君主，（尤指旧时欧洲部份地区小公国的）君主，大公；

例句
Their family has had dukes and marquises for many generations.
他们家世世代代都是公侯.

and

conj. 和，与，而且，于是，然后，因此；

例句
I spend a lot on expensive jewelry and clothing...
我花很多钱购买昂贵的首饰和衣服。

marquises

n. 侯爵夫人，女侯爵( marquise的名词复数 )；

例句
Their family has had dukes and marquises for many generations.
他们家世世代代都是公侯.

for

prep. 为，为了，倾向于，关于，当作；conj. 因为，由于；

例句
I've come looking for a bit of advice.
我特来讨教。

many

adj. 许多，多的；pron. （与复数动词连用）大多数人；

例句
There are many people who still find the act of abortion abhorrent.
仍有很多人对堕胎行为表示厌恶。

generations

n. 代( generation的名词复数 )，（家史中的）一代，产生，一批；

例句
...the absence of strife between the generations that was so characteristic of such societies...
这些社会中典型的代际冲突的缺失