贵州思南县中学2017高考英语阅读理解一轮精编(二)及答案 【2016高考训练】阅读理解—推理判断题。 Expensive perfumes(香水) come in tiny bottles, but many hide a whale-sized secret. To perfect a particular smell, perfume-makers often use an ingredient that comes from sperm whales, called ambergris. But using ambergris, which helps a perfume last longer, is strongly opposed by many people who think it is wrong to kill whales just so we can sweet, Joerg Bohlmann is neither a perfumer nor a whale expert, He's a plant biologist at the University of British Columbia in Canada. But his discovery of a new plant gene(基因) might push whales out of the perfume business. The gene comes from fir trees, found throughout North America and commonly used as Christmas trees. The trees produce a chemical that can be used in perfume in place of ambergris—but with a catch. “There's a problem that many people wouldn't consider. In the tree, the chemical is mixed with many others. That makes separation a challenge,” Bohlmann says.”It's like trying to isolate sugar from a biscuit.” This is where science becomes useful. When Bohlmann learned that fir trees produce the ambergris-like chemical, he decided to use his gene know-how to find the instructions for how to make the ambergris-substitute. Bohlmann found that gene and took it out of the tree cells. Then he did something that might sound strange to someone who doesn't work in genetics: Bohlmann put the gene from the tree into yeast(酵母) cells. |