Explorer （探险者、探测器）of the Extreme Deep 1. Oceans cover more than two-thirds of our planet. Yet, just a small fraction（一部分） of the underwater world has been explored. Now, Scientists at the Woods Hole1 Oceanographic Institution (WHOI) in Massachusetts are building an underwater vehicle that will carry explorers as deep as 6,500 meters (21,320 feet). The new machine, known as a manned submersible（潜艇；潜水器） or human-operated vehicle (HOV), will replace another one named Alvin which has an amazing record of discovery, playing a key role in various important and famous undersea expeditions. Alvin has been operating for 40 years but can go down only 4,500 meters (14,784 feet). It’s about time for an upgrade, WHOI researchers say. 2. Alvin was launched in 1964. Since then, Alvin has worked between 200 and 250 days a year, says Daniel Fornari, a marine geologist（地质学家）and director of the Deep Ocean Exploration Institute at WHOI. During its lifetime, Alvin has carried some 12,000 people on a total of more than 3,000 dives（潜水；跳水）. 3. A newer, better versions of Alvin is bound to reveal even more surprises about a world that is still full of mysteries, Fornari says. It might also make the job of exploration a little easier. “We take so much for granted on land,” Fornari says. “We can walk around and see with our eyes how big things are. We can see colors, special arrangements.” 4.. Size-wise, the new HOV will be similar to Alvin. It’ll be about 37 feet long. The setting area inside will be a small sphere, about 8 feet wide, like Alvin, it’ll carry a pilot and two passengers. It will be just as maneuverable（机动的，可调动的）. In most other ways, it will give passengers more opportunities to enjoy the view, for one thing. Alvin has only three windows, the new vehicle will have five, with more overlap（重叠） so that the passengers and the pilot can see the same thing. 5. Alvin can go up and down at a rate of 30 meters every second, and its maximum speed is 2 knots (about 2.3 miles per hour), while the new vehicle will be able to ascend （上升）and descend at 44 meters per second. It’ll reach speeds of 3 knots, or 3.5 miles per hour. Alvin: 世界上第一个深海潜水器，它最有名的深海探测包括1986年对泰坦尼克号残骸的测量工作。 练习：来源：考试大 1．What is Alvin? A) A research institute. B) A transporting vehicle. C) A submersible. D) A scientist. 2．Which of the following statements is NOT a fact about Alvin? A) It can carry explorers as deep as 6,500 meters. B) It has played a key role in various important undersea expeditions C) It was launched in the sixties of the twentieth century. D) It has been used for more than 40 years. 3. “… a world that is still full of mysteries” refers to A) The earth. B) Out space. C) The ocean. D) Mars.百考试题(www．Examda。com) 4. In what aspects are the new HOV and Alvin similar? A) Size. B) Speed. C) Capacity. D) Shape. 5. In what aspects are the new HOV and Alvin different? A) Offering better views. B) Speed. C) Size. D) Both A and B.