轨道车辆换长如何计算？
参考答案：
换长是车辆换算长度的简称，车辆的换长等于车辆全长除以11。
A．3-n
B．3+n
C．6+n
D．6-n
It's very convenient ______ us to buy train tickets now because we can buy them either from
the station or on the internet.[ ]
A. to
B. of
C. by
D. for
