These will be explicit references to work or labor . . . usually by Marlow. Be prepared to tell what Conrad suggests about work—what conclusion can you draw from these references.
This is a pretty involved question but I'll try to give you a start. There are different references to work. Marlow finds work with a company dealing with staling Ivory and other resources along the Congo river. There are the natives who are forced to work as slaves. There is also Kurtz who turns himself from his job into a sort of demi-god. The Heart of Darkness turns what we perceive as work into something very different.
