Okay. Look at it this way. A disease such as smallpox is either eradicated or eliminated. But which one means what? "Smallpox was eradicated." -- Smallpox was wiped out completely. Gone forever. No further control measures are required. "Smallpox was eliminated." -- Smallpox is reduced in numbers, but not completely gone. Control measures are still needed to prevent further spreading of the disease. In your case... We have to make our best effort to eradicate / eliminate extreme poverty. We have to make our best efforts to eradicate extreme poverty. -- This is almost impossible, but a dream many hope for. Poverty will probably still exist in this world so there's almost no chance of completely wiping it out. We have to make our best efforts to eliminate extreme poverty. -- This is very possible. We can reduce poverty all of the time. I hope this helps!! ~Tutor Stephy (University Student and future Italki Community Tutor!)