generate questions: Six of the seven lines of the commuter rail system, Metrolink, run out of Downtown Los Angeles, connecting Los Angeles, Ventura, San Bernardino, Riverside, Orange, and San Diego counties with the other line connecting San Bernardino, Riverside, and Orange counties directly.
What is the name of the commuter rail system? {sep_token} How many lines does the commuter rail system have? {sep_token} How many lines run out of Downtown Los Angeles? {sep_token} A single line connects San Bernardino, Riverside and what other county? {sep_token}