聽下面短文，根據短文內容選出正確答案．在每題所給的三個選項中，選出一個能回答所提問題的最佳答案，
 16．Where does Mary live？
A．In Shanxi．
B．In Yunnan．
C．In Beijing．
 17．How much is the train fare from Beijing to Shandong？
A．About 140 yuan．
B．About 1，700 yuan．
C．About 600 yuan．
 18．What's the most expensive way to travel from Beijing to Yunnan？
A．By train．
B．By plane．
C．By bus．
 19．Why doesn't Mary go to Yunnan by coach（長途公共汽車）？
A．Because it is expensive．
B．Because it is unpopular．
C．Because it is uncomfortable．
 20．Who will have the shortest journey？
A．Peter．
B．Mary．
C．Sam．