单项选择题
A.only when the cargo is within its rail
B.during the time when loading or unloading is going on
C.after the cargo is checked by tallymen
D.as soon as loading or discharging begins
单项选择题 The payment proportionate to the part of the voyage accomplished or to the part of the cargo delivered is referred as（）.
单项选择题 The majority of cargo gear breakdowns are a result of（）.
单项选择题 The inability to supply a cargo of the contractual quantity in the country of shipment（）the doctrine of frustration into operation.