If you want to see a performance by the Beijing Peking Opera Theatre, which phone number would you ring

A．explain how porters work
B．introduce top-end eateries
C．provide advice on tipping
D．describe how taxis are metered

A．Strengths of paper books over E-books.
B．Projected extinction of paper books.
C．Market prospects of E-books.
D．The history of paper books.