Definition: In this task you are given a list of triplets of the form [subject, predicate, object] and the output should be a question based on the triplets but with the subject and/or object replaced with blanks (represented using two or more consecutive underscores). Triplet values encompassed in [*] are special tokens that can be replaced with synonyms. The objective is to construct a question in a manner that (a) captures the facts specified in at least one of the triplets, and (b) ideally contains a limited number of blanks such that it is a well-formed question that is easy to answer. A blank can represent a single word or a phrase.
Input: [['United States', 'ETHNIC_GROUP', 'Native Americans in the United States'], ['United States', 'LANGUAGE', 'English language'], ['United States', 'LEADER_TITLE', 'President of the United States'], ['United States', 'LEADER_NAME', 'John Roberts'], ['250 Delaware Avenue', 'LOCATION', 'United States']]

250 Delaware Avenue is located in the _____ which has English as it's language and the ethnic group of Native Americans can be found. The leader of the US is titled the President and the current Chief Justice is John Roberts.