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【单选题】
If you are a fan of science fiction, you've no doubt encountered the term nanotechnology. Yet over the past year also, a series of breakthroughs have transformed nanotech from sci-fi fantasy into a real world. Applied science, in the process, inspired huge investments by business, academia, and government. In industries as diverse as health care, computers, chemicals, and aerospace, nanotech is overhauling production techniques, resulting in new and improved products, some of which may already be in your home or workplace. The inspiration for nanotech goes back to a 1959 speech by the late physicist Richard Feynman, then a professor at the California Institute of Technology, titled 'There's Plenty of Room at the Bottom. ' Four decades later, Chad Mirkin, a Chemistry professor at Northwestern University's $ 34 million nanotech center, used a nanoscale device to etch most of Feynman's speech onto a surface the size of about 10 tobacco smoke particles. What accounts for the sudden acceleration of nanotechnology? A key breakthrough came in 1990, when researchers at IBM's Almaden Research Center succeeded in rearranging individual atoms at will. Using a device' known as a scanning probe microscope, the team slowly moved 35 atoms to spell the three-letter IBM logo, thus proving Feynman right. The entire Logo was less than three nanometers. Soon, scientists were not only manipulating individual atoms but 'spray painting' with them as well. Using a tool known as a molecular beam epitaxy, scientists have learned to create ultra fine films of specialized crystals, built up one molecular layer at a time. This is the technology used today to build read-head components for computer hard drives. The next stage in the development of nanotechnology borrows a page from nature. Building a supercomputer no bigger than a speck of dust might seem an impossible task, until one realizes that evolution solved such problems more than a billion years ago. Living cells contain all sorts of nanoscale motors made of proteins that perform. myriad mechanical and chemical functions, from muscle contraction to photosynthesis. In some instances, such motors may be re-engineered, or imitated, to produce products and processes useful to humans. How are these biologically inspired machines constructed? Often, they construct themselves, manifesting a phenomenon of nature known as self assembly. The macromolecules of such biological machines have exactly the right shape and chemical binding preferences to ensure that when they combine they will snap together in predesigned ways. For example, the two strands that make up DNA's double helix match each other exactly, which means that if they are separated in a complex chemical mixture, they are still able to find each other easily. It can be inferred that Richard Feynman has been ______ now.
A.
dead
B.
decent
C.
prominent
D.
popular
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A.
由此可见敬业乐群是秦汉以前儒家对学生学习的一种具体要求。
B.
敬业是向师长学习相关志业,并对之尊敬且亲近。
C.
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D.
敬业乐群就是入读三年后的一项考核标准:即能否心无旁骛、专注学业,能否和乐他人以共同探讨切磋。
【单选题】属于化学灭菌法的是
A.
湿热灭菌法
B.
甲醛灭菌法
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微波灭菌法
D.
紫外线灭菌法
E.
干热灭菌法
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对某种传染病缺乏免疫力容易感染该病的人
B.
没有接种疫苗的人
C.
经常感染传染病的人群
D.
未曾感染过某种传染病的人群
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A.
正确
B.
错误
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A.
热压灭菌法
B.
辐射灭菌法
C.
紫外线灭菌法
D.
火焰灭菌法
E.
环氧乙烷灭菌法
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A.
干热灭菌法
B.
药液灭菌法
C.
湿热灭菌法
D.
射线灭菌法
E.
滤过除菌法
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D.
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A.
加热炉
B.
旋风分离器
C.
反应器
D.
换热设备
【单选题】属于化学灭菌法的是
A.
干热灭菌法
B.
气体灭菌法
C.
湿热灭菌法
D.
射线灭菌法
E.
滤过除菌法
【单选题】属于化学灭菌法的是
A.
辐射灭菌法
B.
紫外线灭菌法
C.
环氧乙烷灭菌法
D.
热压灭菌法
E.
火焰灭菌法
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