单项选择题
How long will the discharging take? （）
A.2 o’clock. B.2 hours. C.2 gangs. D.2 years.
单项选择题 Oil is carried in （）.
单项选择题 This cargo runner is too short. Please （）it for a long one.
单项选择题 The common type of liquid cargo is （）.
