He's been a trade union activist for many years.是什么意思？

He's been a trade union activist for many years.

多年来他一直是工会的积极分子.

been

v. 用来表示某人或某物即主语本身，用来表示某人或某物属于某一群体或有某种性质（ be的过去分词 ），在，存在，不受干扰，去过了，be的过去分词；

例句
Have you been able to have any kind of contact?...
你联系上了吗？

trade

n. 贸易，行业，<美>顾客，买卖；vt.& vi. 交易，经商；vt. 交换，经营…交易，做…的买卖；vi. 贸易，买卖，以物易物；

例句
Argentina has lifted all restrictions on trade and visas are about to be abolished...
阿根廷已经取消所有贸易限制，签证制也将废止。

union

n. 同盟，联盟，协会，工会，联合，团结；adj. 工会的；

例句
They said goodbye to him as he got aboard the train at Union Station.
当他在联合火车站登上火车之际，他们向他道别。

activist

n. 激进主义分子，积极分子，积极行动者；adj. 激进主义的，激进主义分子的；

例句
He's been a trade union activist for many years.
多年来他一直是工会的积极分子.

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。

years

n. 年( year的名词复数 )，年纪，一年的期间，某年级的学生；

例句
His wife was sentenced to seven years imprisonment for aiding and abetting him...
他的妻子作为他的从犯被判入狱7年。