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  3. Out in the Atlantic the other day, in about 3,000 feet of water and about 120 miles east of Charleston, S. C., a converted cargo

Out in the Atlantic the other day, in about 3,000 feet of water and about 120 miles east of Charleston, S. C., a converted cargo

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问题     Out in the Atlantic the other day, in about 3,000 feet of water and about 120 miles east of Charleston, S. C., a converted cargo vessel dropped a string of nine-inch-diameter steel pipe to the ocean floor. Operating somewhat like a vacuum cleaner, it began to suck into the ship a thundering stream of air, water, and nodules—smooth apple-sized lumps—of rich metallic ore.
    From the Research Vessel Deepsea Miner, a jubilant crew of scientists, engineers and sailors flashed the word back to the headquarters of Deepsea Ventures, Inc., "It works." they reported, beyond expectations. (This successful first test of a revolutionary technique for mining an untapped source of four important metals was only a single step in a long march, much of which still lies ahead of Deepsea Ventures.) The test, however, was one of the biggest strides so far in a program that has absorbed about eight years and $15 million.
    Company officials indicated here last week that the success probably had answered favorably the major questions about the mining techniques involved. Questions that still remain concern the international legal status of the widespread ocean-bed deposits, the processing and refining of the unique type of ore they contain and the economics of marketing the manganese, nickel, cobalt and copper that would be produced.
    To operate commercially, a consortium would have to begin in the Pacific with a specially built, full-scale mining ship, capable of recovering nodules at depths of 15,000 or 8,000 feet. Pacific deposits are richer and more likely to prove economically feasible than the Atlantic ore that was recovered in the recent exercise, designed strictly to test the recover technique.
    Also, the mining ship would probably have to be served by transports, which would take the ore to a refinery ashore. This refinery, moreover, would have to be a pioneering project because conventional processing techniques would not work on manganese nodules.
    The origin of the ocean-floor deposits is uncertain, but they were probably formed 10 million to 30 million years ago through a natural process somewhat like the electrochemical technique used to manufacture nickel or copper cathodes. They always have a nucleus, such as a pebble, a shark’s tooth or a whale’ s ear bone.
    Thus in broad terms, the atomically bonded elements can only be recovered by reversing the electro-chemical process, which Deepsea Ventures already is doing on a limited scale in a small pilot plant. A bigger pilot plant-to use the same jealousy guarded techniques is under construction a few yards away.
选项 A、Ocean Nodules
B、Success in the Ocean
C、Scraping the Ocean Bottom
D、New Sources of Ore
答案D
解析 根据文章的第一段中的最后一句rich metallic ore以及文章的中心，可知这篇文章主要讲的是金属矿的开发，所以选项D最符合题意。
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