单项选择题 The greatest strain，when lifting a load with the jumbo purchase，is on（）.

单项选择题 The（）should ensure that the holds in which chemical packages are stowed are properly supervised during the loading operations and these packages are regularly inspected for leakage or damage on the voyage.

单项选择题 Sea water temporarily pumped into tanks to simulate the increased vertical loading of environmental forces is termed（）.