Jeremy Kerr, a researcher at the University of Ottawa in Canada, and his colleagues analyzed more than 400,000 observations of bumblebee species collected in North America and Europe from 1975 to 2010. When the researchers recorded the locations of these bee populations, they found that many of the 67 species analyzed were moving northward from their southern limits while the northern edges of the bees' ranges are staying in place. What it results in is obvious. Bees have been paid more attention to in recent years, with populations of honeybees and bumblebees obviously declining in some parts of Europe. Previously, attention on the decline of bee populations has focused on causes including habitat loss, pesticide use and the spread of bee parasites . But the work by Kerr's team found something different. "For every species, there is one or two species declining and others that are not moving at all," says Kerr. This shift has also been observed in other species, such as butterflies. But due to a new cause -- the rise of temperatures instead of total pesticide use, a change in land use or parasites, bumblebees -- unlike butterflies -- have failed to extend the northern boundaries of their ranges into the territory that is now habitable for them, so bumblebee species across Europe and North America are declining rapidly, the latest study led by Kerr's team finds. "Our data suggest that the new factor plays a leading, or perhaps the leading, role in this trend," says Kerr. "This study shows that a fourth factor is also beginning to affect it. It is likely that the combined stresses from all of these pressures will have destructive impacts on bumblebees in the not-too-distant future," says Dave Goulson, a bee researcher at the University of Sussex, Brighton, UK. Exactly what can be done to help bumblebees is not clear. Kerr's team suggests that relocating colonies might be an answer but Goulson says that because the insects are mobile they are capable of moving northwards if there is suitable habitat available. What does the move of the bees' southern limits lead to? A) The birth of new bee species. B) The rise of the bees' population. C) The evolution of the bees. D) The reduction of the bees' habitat.
D
(Question)
I've lived my whole life in Spanish Harlem with my mom, and I never have a father. I have friends who ended up in jail or pregnancy. But Mr.Clark wouldn't let that happen. Mr. Clark worked long hours, making sure I did my work. My grades rose. In fact ,our whole fifth-grade class's scores rose in math and reading. In sixth grade, I entered the gifted program, and Mr. Clark was the teacher. I felt so lucky to have him for a second year ! None of us were surprised when Mr.Clark was selected as Disney's 2004 Teacher of the Year. When he learned he'd won, he said he would draw three names out of a hat; those students would go with him toprefix = st1 /Los Angelesto get the award. But when it came time to draw names, Mr. Clark said, " You're all going." He got donations to fly all 37of us out to Disneyland inCaliforniaand put us at the Hilton. We were there for three days. People were amazed, but Mr. Clark really cared about us. There's no way I can imagine most teachers doing that. No way. But he saw something in us that nobody else saw. On graduation day ,there were a lot of tears. We didn't want his class to end. In 2005,he moved toAtlanta, but we always kept in touch. He started giving speeches about education and wrote a best-selling book based on his classroom rules. In 2007,Mr.Clark took some of us on a trip toSouth Africato deliver school supplies and visit orphanages. It was the most amazing experience of my life. It's now my dream to start a group of women's clubs one day, helping people from all backgrounds. I'm about to become a senior atHarlemRenaissanceHigh School. My grades are beautiful now, and I'm hoping to go to law school eventually. This fall, Mr.Clark will be opening the Ron Clark Academy inAtlanta, a school for kids who have potential but aren't reaching it, kids who are like I was -- until Mr.Clark came along. What was the author's attitude toward Mr. Clark? A) Amazed. B) Satisfied C) Grateful. D) Admiring.
(Answer)
C
Believe it or not, in the near future people won't just wear a chicken feather suit at Halloween or for fancy dress. Chickens, which have long provided food for dinner, will also be used to make our clothes as well. Last Monday, a report by the University of Nebraska in the US said in the future it should be possible to use chicken feathers and rice straw to make clothes. "All those wasted agriculture products don't have to be wasted anymore," researcher Yiqi Yang said. New technology will change these by-products into something similar to wool, linen, or cotton. Because producing synthetic fabrics causes pollution, scientists wanted to find a cheaper and environmentally friendly replacement. They turned their eyes to the millions of tons of rice straw and chicken feathers that are widely and cheaply available worldwide. Moreover they don't cause pollution like petroleum-based fibers . Chicken feathers are mostly made up of the same kind of protein found in wool. A sweater made from chicken feathers would feel just like a wool sweater. It would be lighter in weight and warmer, too. According to Yang and his team, rice straw, on the other hand, can produce a fabric that looks and feels similar to cotton or linen. The process is also environmentally friendly. The total production cost of rice fiber is about 50 cents per pound, while cotton now sells for about 60 cents a pound. Maybe some day in the future you will wear _ clothes like these. What are the main advantage of the new clothes made of chicken feathers and rice straw? A) They are mostly made up of the same kind of protein found in wool. B) The clothes will be widely used in every field in our daily life. C) The process of producing the clothes does not cheap at all. D) A sweater made of the new clothes would be lighter in weight and warmer.
D