Part A: a place where a specific group of people used to stay
Part B: “proved to have deep roots”
Explanation:
As can be seen in the paragraph shown in the question above, the word "haunt" was used in the sense of "to group," referring to a place where a specific group of people usually stays. This expression was used in the article to show how difficult it is to end terrist organizations when they are trapped, joined, haunted in the Middle East, where they established deep and difficult roots to be destroyed.
In this case, we can say that the detail of the paragraph that supports the word "haunt" is the detail that shows that terrorist organizations "proved to have deep roots" in their homeland.
