ScientistsattheUniversityofGeorgiarecentlyshowedthatth...

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  Scientists at the University of Georgia recently showed that the control of a single gene in a hardwood tree species makes it grow faster and break down into fuel more easily.

  The growth rate increase was a surprise. Researchers at Georgia were focused on weakening the species’ defenses to chemicals used to take out of the sugars to create biofuels（生物燃料）. They were able to aim at a gene called GAUT12.1, important sections of the protective cell walls in plants.

  “This research gives us important suggestions about the genes that control plant structures and how we can use them to our advantage.” study co-author Debra Mohnen, a professor of biochemistry at Georgia, explained.

  “The difficulty of breaking down the complex plant cell wall is a major barrier to the cost-effective production of biofuels, and this discovery may pave the way for new techniques that make that process more economically possible,” Mohnen added. In the lab, researchers engineered 11 transgenic(转基因的) trees, with GAUT12.1 decreased by approximately 50 percent.

  “Our experiments show that the trees we created were less unmanageable, meaning that it would be easier to obtain sugars from the plant cell walls,” said lead study author Ajaya Biswal, an assistant research scientist in Mohnen’s lab. “ But we were particularly happy to see how quickly these trees grew compared to what one would observe in with the wild type.”

   The trees grew especially fast. Eastern cottonwoods, the employed species, are already prized for their rapid growth. The transgenic trees matured（成熟） even faster- reaching a 12 to 52 percent increase in height and a 12 to 44 percent increase in diameter（直径） when compared to the control group.

   “ We’ve already learned a lot from this process, but we are confident that we can expand and improve on our research to achieve even better plant materials used as fuel and understanding of how it is produced,” Mohnen concluded.

32. What can we know about GAUT12.1 from the text?

  A. It gets rid of all sugars           B. It does harm to trees.

  C. It is found in every plant.         D. It protects tree’s cell walls.

33. It can be inferred from the text that _____________.

  A. the scientists will go on with their research.

  B. there are many genes helping trees’ growth.

  C. the researchers are dissatisfied with what they’ve achieved.

  D. eastern cottonwoods grow more quickly than any other trees

34. Which of the following is key to the production of biofuels?

  A. Protecting the plant cell wall.          B. Planting the wild trees in the lab.

  C. Making the trees grow more quickly.    D. Breaking down the complex plant cell wall.

35. What type of reading is the text?

  A. Science report.                      B. Economy survey.

  C. Entertainment news                  D. Travel guidance.

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