题目

阅读理解 When she looked ahead，Florence Chadwick saw nothing but a solid wall of fog.Her body was numb (麻木的)．She had been swimming for nearly sixteen hours. Already she was the first woman to swim the English Channel in both directions.Now，at age 34，her goal was to become the first woman to swim from Catalina Island to the California coast. On the morning of July 4th，1952，the sea was like an ice bath and the fog was so thick that she could hardly see her support boats.The wind was strong and it was raining heavily.Against the cold water of the sea，she struggled on—hou1．某粮仓有30吨粮食，上午运走9.75吨，下午比上午多运多少吨才能在一天内全部运完？