a cave,but it was not discovered until 1905.In that year,a thirteen-year-old boy named Ben Sands crawled through a small opening three hundred feet underground.He found himself in a large cave half filled with water. Today tourists visit the Lost Sea and ride far out onto it in glass-bottomed boats powered by electric motors.More than thirteen acres of water have been mapped out so far and still no end of the lake has been found.Even though teams of divers have tried to explore the Lost Sea,the full extent of it is still unknown. 21.The Lost Sea is unique because it is A.part of a historic cave system B.the biggest underground lake in the world C.listed in the Guinness Book of World Records D.the largest body of water in Tennessee 22.The Craighead Caverns have been known A.throughout history B.since the time of the Indian nations C.since 1905 D.as divers explored them 23.Who located the Lost Sea in recent times? A.The Cherokee Indians. B.Tourist. C.Ben Sands. D.Scientists. 24.What was found in“The Council Room”? A.A small natural opening. B.A large cave. C.Another series of rooms. D.Many old Indian objects. 25.It can be inferred from the passage that the Craighead Caverns presently serve as A.an underground testing site B.an Indian meeting ground C.a tourist attraction D.a motorboat race course Questions 26~30 are based on the following passage. The dog has always been considered man's best friend.Always noted for being particularly faithful in watching over children,he also has his place by fireside,in the cow pasture,on the sheep range,and beside the hunter in forest or blind.He is easy-to train, works hard,and often performs astonishing feats.And in the frozen polar regions he was once the principal motive power,before being largely displaced by the plane and helicopter. Because he howls or whines(哀鸣)in the presence of impending(即将发生的)death,the 958a cave. but it was not discovered until 1905. In that year. a thirteen-year-old boy named Ben Sands crawled through a small opening three hundred feet underground. He found himself in a large cave half filled with water. Today tourists visit the Lost Sea and ride far out onto it in glass-bottomed boats powered by electric motors. More than thirteen acres of water have been mapped out so far and still no end of the lake has been found. Even though teams of divers have tried to explore the Lost Sea. the full extent of it is still unknown. 21. The Lost Sea is unique because it is A. part of a historic cave system • B. the biggest underground lake in the world C. listed in the Guinness Book of World Records D. the largest body of water in Tennessee 22. The Craighead Caverns have been known • A. throughout history C. since 1905 B. since the time of the Indian nations D. as divers explored them 23. Who located the Lost Sea in recent times? A. The Cherokee Indians C. Ben Sands. B. Tourist. D. Scientists. 24. What was found in "The Council Room"? A. A small natural opening. B. A large cave. C. Another series of rooms. D. Many old Indian objects. 25. 巾n be 恤r时from tl叫assage 阳the Cra胁ead Caverns presen句serve as • A. ah underground testing site C. atourist attraction B. an Indian meeting ground D. a motorboat race course Questions 26~30 are based on the following passage. The dog has always been considered man' s best friend. Always noted for being particularly faithful in watching over children. he also has his place by fireside. in the cow pasture. on the sheep range , and beside the hunter in forest or blind. He is easy-tQ train , works hard , and often performs astonishing feats. And in the frozen polar regions he was once the principal motive power , before being largely displaced by the plane and helicopter. Because he howls or whinesC in the presence of impendingC 的)death the 958