I've just graduated from university.

我大学刚毕业。

I graduated from university 8 years ago.

我大学毕业已经8年了。

Well, l've just graduated from university.

噢，我刚从大学毕业。

A I graduated from university about 5 years ago.

A大约5年前我从大学毕业。

I graduated from university of agriculture.

我是农业大学毕业。