Oceans cover more than two-thirds of our planet. Yet, just a small fraction of the underwater world has been unexplored. Now, Scientists at the Woods Hole 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) 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.
"Alvin was launched (发动) in 1964. Since then, Alvin has worked between 200 and 250 days a year", says Daniel Fornari, a marine geologist (地址学者) 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. "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."
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). 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 so that the passengers and the pilot can see the same thing.
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 and descend at 44 meters per second. It"ll reach speeds of 3 knots, or 3.5 miles per hour.
单选题
What is Alvin?
【正确答案】
C
【答案解析】[解析] 根据文章第一段第四句“The new machine, known as a manned submersible or human-operated vehicle (HOV), will replace another one named Alvin...”可知Alvin与HOV一样都是潜艇，故本题选C。
单选题
Which of the following statements is NOT a fact about Alvin?
【正确答案】
A
【答案解析】[解析] 根据文章第一段第四、五句“...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...”可知，Alvin在各种深海探测中发挥了重要的作用，Alvin已经运行了40年，但它只能潜到4500米的深处，所以A项说法错误，B项和D项正确。根据文章第二段第一句“Alvin was launched in 1964”可知Alvin从1964年开始使用，所以C项正确。故本题选A。
单选题
"...a world that is still full of mysteries" refers to ______.
【正确答案】
C
【答案解析】[解析] 文章第一段第一、二句“Oceans cover more than two-thirds of our planet. Yet, just a small fraction of the underwater world has been unexplored.”就指出，人们只探索了海洋的一小部分，且全文都在围绕探索海底世界的潜艇展开叙述，故本题选C。
单选题
In what aspects are the new HOV and Alvin similar?
【正确答案】
D
【答案解析】[解析] 根据文章第三段前三句“Size-wise, the new HOV will be similar to Alvin. It"ll be about 37 feet long. The setting area...about 8 feet wide, like Alvin...”可知HOV和Alvin在体积上和容量上相似，故本题选D。
单选题
In what aspects are the new HOV and Alvin different?
【正确答案】
D
【答案解析】[解析] 根据文章第三段最后两句“...it will give passengers more opportunities to enjoy the view...the new vehicle will have five...”可知HOV有五个窗户，所以乘客视野更宽阔，故A项正确。根据最后一段“Alvin...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...reach speeds of 3 knots, or 3.5 miles per hour.”可知两种潜艇的速度有所差别，HOV更快，所以B项也正确。故本题选D。