Bill of lading by the carrier only to add "weightunknown" clause to protect themselves.
承运人只有通过在提单中加入“重量不知”条款才能保护自己。
2
The study concluded that "the mechanism of this weight loss is unknown [but] it would appear reasonable to include grapefruit in a weight reduction diet."
研究得出结论是这种减轻体重的机制还未知道，但相信包括葡萄柚等类似的减肥饮食的合理原因会浮出水面的。
3
Use a wire sling of a greater S. W. L whenever the exact weight of the load is unknown or there is a hazard to personnel.