为了给备战2015年英语六级的考生朋友助力，出国留学网每天都会为大家准备英语六级选词填空练习题，希望可以借此提高你的阅读水平。今天一起来了解一下纳米技术的前世今生吧。每天练习一题，每天进步不止一点点!
2015英语六级选词填空练习：纳米技术
Today nanotechnology (纳米技术) is still in a formative phase. Yet it is maturing rapidly. Between 1997 and 2005, investment in nanotech research and development by governments around the world ____36____from $ 432 million to about $ 4. 1 billion, and corresponding industry investment exceeded that of governments by 2005. By 2015, products incorporating nanotech will contribute approximately $1 trillion to the global economy.
Descriptions of nanotech typically characterize it purely in terms of the minute size-assemblies between the size of an atom and about 100 molecular diameters (分子直径). That____37____makes it sound as though nanotech is merely looking to use infinitely smaller parts than conventional engineering. But rearranging the atoms and molecules leads to new____ 38____ One sees a transition between the fixed behavior of individual atoms and molecules and the adjustable behavior of collectives. Thus, nanotechnology might better be viewed as the ____39____ of quantum theory (量子论) and other nano specific phenomena to fundamentally control the properties and behavior of matter.
The second stage, which began in 2005, focuses on active nanostructures that change their size, shape, conductivity or other properties during use. New drug delivery particles could release therapeutic(治疗的) molecules i...