Sentence:  When we look at countries like Iran , Iraq , Pakistan , and Burma , where substantial progress has been made in creating a minimum supply of modern men and of social overhead capital , and where institutions of centralized government exist , we find a second category of countries with a different <WSD>set</WSD> of problems and hence different priorities for policy . 
Meaning of the word marked with <WSD> tags:  a group of things of the same kind that belong together and are so used