我曾担任经济系学生会主席的翻译：I was Chairman of the Department of economics students ' Union 什么意思？中文翻译英文，英文翻译中文，怎么说？

青云英语翻译

I served as Chairman of the Department of Economics Students' Union

I was Chairman of the Department of economics students ' Union

I once held the post of economics department student association president

I have been at the head of the President of the students' union

I was Chairman of the Department of economics students ' Union