单项选择题
A．eat their food slowly B．help the host serve food C．serve each other at the table D．help themselves to more food
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