单项选择题
A．while the guests are having small talks B．when all the guests have arrived C．after the guests finish small talks D．after the dinner comes to an end
A．buses are always available in 24 hours B．bus riders have to buy monthly passes C．bus fare is paid by exact change in coins D．buses are the best means of transportation
A．at bus stations B．at local banks C．in any bookstores D．from the ticket offices