2016年秋湖北重点高中联考协作题期中考高三英语试题及答案(7)
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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 (龙涎香). 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
smell 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. "lt'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.
Yeast may sound familiar because it's used to make things like bread, wine and beer.
Biologists like to work with yeast because it easily adopts new genes and changes its features
and behaviour. When Bohlmann put the fir tree gene into the yeast, the yeast started making
the same chemical that had been produced by the tree.
Perfumers pay big money for ambergris because it is a fixative, which means it holds a
smell in place on a person's body.
"Cheap perfumes smell good in the first hour or so and then everything is gone," explains
Bohlmann. "But expensive perfumes are much more stable. Their smell lasts much longer, for
hours or even a day after you apply them. "
The new chemical, made from the tree genes, can be used as a fixative, too. And using
yeast to make it is far cheaper than acquiring ambergris.
Bohlmann admits he never thought he'd get into the perfume business. But now, he says,
producers have been calling to find out how to use his technology in new perfumes.
32. It can be inferred from the passage that if a perfume contains ambergris, .
A. its user probably supports whale hunting
B. its smell will last for about an hour
C. it is probably very expensive
D. there will be a whale symbol on the bottle
33. The underlined expression "with a catch" in Paragraph 3 means____.
A. being difficult to hold B.being too similar
C. needing further testing D. having a hidden problem
34. According to the passage, why are yeast cells often used in genetic research?
A. They're much cheaper to use than ambergris.
B. They can reproduce much faster than other cells.
C. They share some of the qualities of plant genes.
D. They can take on the characteristics of other genes.
35. What can we learn about Joerg Bohlmann from the passage?
A. He has previously done genetic research.
B. He made his discovery during Christmas.
C. He has worked in the perfume industry for many years.
D. He is opposed to whale hunting.
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