sentence: Social cards are free for senior citizens and reduced for students.
sentences_before: The moscow metro uses magnetic cards for tickets with a certain number of rides. These rides must be used within 30 days after the first ride. These tickets were first sold in 1993 as a test. There are two kinds of smartcards, 'unlimited' and 'social'.
concept_name: social card
headings: Moscow Metro Tickets
categories: Moscow Rapid transit systems