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.
A.is capable of bringing B.is sufficient to bring C.is not capable of bringing D.is probally to bring
单项选择题 The full utilization of berths can be achieved if（）.
单项选择题 The foreman says that the stevedores stopped working owing to the（）of the winch.
单项选择题 The force acting on a single cargo runner which is vertically lifting or lowering a load is greatest when（）.
