单项选择题 Under normal weather and sea conditions when securing a stack of containers with non-locking fittings，lashings are required when the tier exceeds what height?（）.

单项选择题 Under the Carriage of Goods by Sea Act of 1936，a vessel will be liable for damage to cargo when the damage arises out of（）.

单项选择题 What is NOT an advantage of containership operations over conventional break-bulk operations? （）.