听力原文： Many of the heroes of all times have been distinguished men of the sea. Such a man was Thomas Scott. (15[D])Captain Scott performed many brave deeds, but perhaps his most remarkable act was the saving of hundreds men, women, and children (16[A])who were crossing the Hudson River in a ferryboat. It was winter and the river was full of blocks of ice. As the ferry boat crossed the river, a tugboat ran into her. The collision cut a great V-shaped hole in her side. Men, women, and children were soon screaming with fright as the water poured into the engine room. In a few minutes the boat would have sunk, plunging all the passengers into the icy water. Fortunately, Captain Scott happened to be passing in a river tugboat. He quickly pulled his boat up to the sinking ship and sprang to her deck. Rushing down to file engine room, he plugged the hole with everything he could find. Still, water came in. (14[C])Then he thrust his arm into the hole and stopped the water with his body. For an hour he held back the water until the boat reached the dock and everyone was saved. It can be inferred that Scott was a hero because ______.