hard的副詞？

　　People tend to work hard at this stage of life.

　　人在這個人生階段往往發奮努力。

　　Her job is hard work, but the pay is good.

　　她工作雖辛苦，但薪水不低。

　　When I left they were all still hard at it.

　　我離開的時候他們都還在努力工作。