单项选择题 Where a charter-party specifies the estimated time of arrival of a vessel at the port of loading，there is（）obligation on the shipowners to sail to there on the date on which when proceeding with all convenient speed it would normally reach the port on or about the estimated date of arrival.

单项选择题 When the carrier is liable for compensation in respect of loss of or damage to the goods such （）shall be calculated by reference to the invoice value of the goods plus freight charges and insurance if paid.

单项选择题 When a vessel violates the oil pollution laws，who may be held responsible?（）