What is the most cited word? How many papers was that word cited in?
most cited word refers to max(count(word_cited_id);
SELECT word_cited_id, COUNT(paper_id) FROM content GROUP BY word_cited_id ORDER BY COUNT(word_cited_id) DESC LIMIT 1
database name:db_id citeseer
cites table cites Cols: cited_paper_id dtype text, citing_paper_id dtype text, 
paper table paper Cols: paper id dtype text, class label dtype text, 
content table content Cols: paper id dtype text, word cited id dtype text, 
