Problem: What are the most important words?
map from which users can select the district in which they want to browse hospitals .
Answer: district, hospital, map, user, want

Problem: What are the most important words?
politician delivers a speech during a rally calling for peace ahead of election .
Answer: deliver, peace, politician, speech

Problem: What are the most important words?
students learn the fundamentals on gas and oil through science .
Answer:
learn, oil, science