WASHINGTON--Two-thirds of the world's polar bear population could be gone by 2050 if predictions of melting sea ice hold true, the US Geological Survey reported on Friday. The fate of polar bears could be even worse than that estimate, because sea ice in the Arctic might be disappearing faster than the available computer models predict, the geological survey said in a report aimed at determining whether the big white bear should be listed as a threatened species. "There is a definite link between changes in the sea ice and the welfare of polar bears," said Steve Amstrup, who led the research team. He says Arctic sea ice is already at the lowest this year and is expected to retreat farther this month. That means that polar bears--some 16,000 of them -- will disappear by 2050 from parts of the Arctic where sea ice is melting most rapidly, along the north coasts of Alaska and Russia, researchers said in a telephone briefing . Other polar bears could survive beyond that date but many of those could be gone by 2100, Amstrup said. By this century's end, the only polar bears left might live in the Canadian Arctic islands and along the west coast of Greenland. "It is likely to result in loss of approximately two-thirds of the world's current polar bear population by the mid 21st century," the report's executive summary said. "Because the observed trajectory of Arctic sea ice decline appears to be underestimated by currently available models, this assessment of future polar bear status may be conservative ." In January, the US Fish and Wildlife Service proposed listing the polar bear as a threatened species, noting polar bears depend on sea ice as a platform to hunt seals, their main food. Without enough sea ice, polar bears would be forced onto land, but they are poor hunters once they get out of the water and ice, the researchers said. The bears' disappearance would probably take place as young cubs failed to survive to adulthood and females were unable to reproduce successfully. What causes the polar bears to disappear by 2050? A) The pollution of the Arctic region. B) The sea ice melting at high speed C) Fewer food sources being left. D) The temperature getting colder.
B
(Question)
Over the past decade, cheating--an act of academic dishonesty--has become more and more common. The latest statistics shows more than two thirds of high school students admitted cheating on an exam last year, and--even more surprising--often the best students cheat to get to the top of their class--and they don't think it is wrong. It's not a big deal. Everybody is doing it. It is a big deal! Cheating is basically wrong and must be punished. If students easily get away with it, they might be encouraged to do it again. They won't realize that this--in the broadest sense--is an attack on our society, which is based on values like honesty and fairness. The present spreading of cheating indicates a loss of those values and cannot be tolerated. An appropriate punishment for cheating incidents would make students aware of their misbehavior. If no one were punished for cheating, who would ever study for an exam? Tons of papers would be _ from websites, writing crib sheets would be more important than reviewing the subjects, and highly sophisticated cheating arts would be invented. Knowledge would only exist on the Internet and on cleverly created cheat sheets, but not in the minds of the students--a rather bad precondition to enrich our society wisely and intelligently. Students have to learn that they have to learn. Only doing what's right will bring them a feeling of pride and accomplishment and create self-confidence--the building blocks for a successful and satisfying life and a society that keeps its values. How can students create self-confidence? A) By knowing they have to learn. B) By doing what is right. C) By learning the right things. D) By being punished when cheating.
(Answer)
B
One day several years ago,Josie went to collect her sister from her local Harvester pub in Brentwood,Essex,where they both worked.A few men came up with gulls in their hands.The robbers then tied up their arms and legs and told them to get down on the ground,while they _ the restaurant,fleeing withPS1,000. "As I lay on the ground I felt helpless and ashamed as they took time out to laugh at me,calling me fat cow,''Josie said.Shortly after that she was able to untie herself and raise the alarm,but it was just the beginning of her nightmare. "I was too terrified to go back to work,so I had to leave.I slept with the light on for more than a year.My confidence was totally destroyed.At school people would call me fatty and shout nasty things.When the robber called me fat that night,it just brought all those horrible memories back.''Over the next few months Josie ate more and piled on more pounds as she tried to cope with the sufferings. Two years went by and Josie stuck to the same bad habits,which worried her family a lot.In order to wipe the cloud off and cheer her up,her sister suggested a trip.It wasn't until returning from the family holiday on the island of Aruba that she decided to take action once and for all and signed up for Weight.Watchers the next day with her sister. Eighteen months 1ater,a slimmer and happier Josie flew to Turkey in summer in 2012 with her family,where she met sailor Fatih,26,at a party and the pair:plan to get married next summer."If you had told me three years ago that I would be marrying a handsome Turkish man, and looking for a size 10 wedding dress,I would have never believed you." When did Josie decide to lose weight? A) After she heard the:robber's words. B) When she met the sailor Fatih. C) After she graduated from school. D) After she finished the tour of Aruba.
D