The color red often means danger -- and by paying attention, 1 can be prevented. At railroad crossings, flashing red lights warn cars to stay back. A red light at a traffic intersection tells cars to stop, so 2 dont run into other cars.
In the future, the color red also may help prevent danger 3 construction sites. Thanks to new work by engineers, bridge supports- or other kinds of materialscould one day contain a color-changing material. It will turn red 4 a structure collapses or falls 5 A tiny molecule may make a big difference in future warning systems.
A polymer6 a color-changing molecule called a mechanophore turns red seconds before it snaps. The technology may one day allow damage to materials or structures to be easily 7 .
The secret behind the color-changing material is a particular type of molecule. A molecule is a group of atoms held together by 8 bonds. Molecules come in all shapes and sizes, and make up 9you can see, touch or feel. How a molecule behaves depends on what kinds of atoms it contains, and how theyre held together.
When a polymer containing a color-changing molecule called a mechanophore is about to breaks, it produces a color. When a polymer with mechanophore molecules becomes injured or 10, one of the mechanophore bonds breaks and the material turns red. Its a really simple detection method, says Nancy Sottos, one of the scientists who worked on the project. Were 11 up this one bond, and it changes color. Sottos and her team tested the color-changing polymers in their lab. The test12 proved encouraging.
There is a way to get rid of the red color: 13. When a bright light is shone on the mechanophore, the broken bond is fixed - and the red color disappears. This self-healing may be a problem for engineers. They need to use the color-changer in big construction projects that will be 14 , in sunlight. And sunlight will make the mechanophores warning system useless.
Sottos and her fellow scientists still have 15 work to do before the color-changing molecules can be used outside the lab.
练习:
1. A measures
B accidents
C actions
D collapses
2. A they
B it
C some
D most
3. A with
B over
C at
D in
4. A before
B after
C once
D while
5. A together
B behind
C down
D apart
6. A contacting
B conducting
C containing
D considering
7. A controlled
B spotted
C repaired
D changed
8. A technical
B electronic
C physical
D chemical
9. A everything
B something
C nothing
D anything
10. A weak
B strong
C tough
D soft
11. A using
B opening
C turning
D finishing
12. A laws
B theories
C tools
D results
13. A air
B electricity
C light
D sound
14. A aside
B beside
C inside
D outside
15. A a part of
B a pair of
C a piece of
D a lot of
参考答案
BACAD CBDAA BDCDD
2015职称英语考试理工类AB级阅读判断(2)
职称英语理工类考试教材阅读理解重点文章以及译文(3)
职称英语考试综合类阅读理解备考练习题以及答案(1)
综合类职称英语考试阅读理解精选的练习题(2)
2015综合类职称英语考试新增内容阅读理解篇(3)
2015职称英语考试理工类阅读理解专项练习题(1)
2015职称英语理工类阅读理解专项训练(5)
2015阅读理解职称英语综合类练习题(1)
2015年阅读理解职称英语考试综合类精选练习(5)
职称英语理工类考试教材阅读理解重点文章以及译文(6)
2015职称英语理工类教材新增内容阅读理解篇(3)
阅读理解考试《综合类》职称英语练习题以及答案(1)
2015职称英语考试理工类阅读理解复习题(3)
2015职称英语考试理工类阅读理解复习题(4)
阅读理解职称英语综合类强化练习以及答案(3)
2015综合类职称英语考试新增内容阅读理解篇(5)
综合类职称英语阅读理解考试练习以及答案(2)
阅读理解职称英语综合类强化练习以及答案(1)
2015年职称英语A级阅读理解综合类精选练习题(4)
2015阅读理解职称英语综合类练习题(4)
2015综合类职称英语考试新增内容阅读理解篇(2)
2015职称英语考试理工类阅读理解基础复习题(1)
2015阅读理解职称英语综合类练习题(5)
综合类职称英语考试阅读理解精选的练习题(4)
综合类职称英语考试阅读理解的精选练习题(3)
2015职称英语考试理工类阅读理解必备精选练习题(5)
职称英语理工类考试教材阅读理解重点文章以及译文(2)
综合类职称英语阅读理解考试练习以及答案(3)
2015职称英语考试理工类阅读理解必备精选练习题(3)
阅读理解职称英语考试综合类精选练习(4)
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |