20.Though"nanometer"(納米) is now a fashionable term all over the world,few people know exactly what it is.It has become a new favorite of manufacturers and sellers in recent years.Many"high-tech"products bearing the name"nano"have entered the market,bringing more mysterious feeling to surprised consumers.
Nanometer is a very small length unit of measure,and is very small.One millimeter is 1000micrometers,and one micrometer is 1000nanometers.That is,one nanometer is one billionth of a meter.Nano materials are solid materials composed of particles(粒子) or crystallites(晶體) of less than 100nanometer in size.Then,is a cup made of nano material really any different from an ordinary cup in function as far as how it works?
Are nano cups really so wonderful?A reporter went to the Institute of Nanomedicine,which is the first such institute of such a sort in the world and the only one in China,specializing in researching the investigation of the application of nano technology into medicine.
A water molecule(分子) is composed of 2hydrogen atoms and 1oxygen atom.It can be changed only by special working skillfully of the atoms.The material making up the cup can have nanometer particles.But it cannot change the chemical and physical propertiesof the water contained in it.The water in the cup is still water.When people drink it,it will produce no special effect on human body.
Professor Ji who worked in the Instiute of Nanomedicine told the reporter,so far,the investigation of nano materials is still limited in the laboratory.No commercial micro products can be produced yet.With the present level of science and technology,the time of everyday goods made of nanometer materials is still years away.
The products labeled with nano marks in the market now are only traditional products coated with a thin layer of nanometer material,which makes them more abrasion resistant(耐磨),much easier to be cleaned,or oil resisting or moth proof(防蛀).
Professor Ji explained that nano cup is a real cup.It can also be included in the list of nano products in a certain sense.But the nano cup has not changed its property and function as a cup.It is not a magical medicine for curing and health care.
67.Which of the following shows the right relationship?A
A.nanometer<micrometer<millimeter<meter
B.micrometer<millimeter<nanometer<meter
C.nanometer<millimeter<micrometer<meter
D.millimeter<micrometer<nanometer<meter
68.It can be inferred from the passage thatD.
A.real nano products are being produced by some companies
B.nano materials have been put into use in daily goods
C.the nano cup is very effective in curing and health care
D.real nano products haven't become available for people
69.The underlined word"properties"in the fourth paragraph probably meansC.
A.possessions B.reactions C.qualities D.symbols
70.What would be the best title for the passage?B
A.High-tech Products B.Nano Materials
C.High-teach Research D.Nano Cups.
分析 本文是一篇科教類閱讀,主要介紹了什么是納米材料及其目前的研究進展.
解答 67-70 ADCB
67題答案:A考查細節(jié)推理,根據(jù)原文第二段One millimeter is 1000micrometers,and one micrometer is 1000nanometers.可知本題答案為A選項.
68題答案:D考查細節(jié)推理,根據(jù)原文第四段的With the present level of science and technology,the time of everyday goods made of nanometer materials is still years away.由于目前科學技術(shù)的局限,用納米材料制造日常用品的時代還很遠.可知本題答案為D選項.
69題答案:C考查細節(jié)推理,根據(jù)后面的The water in the cup is still water.可知"納米材料杯并未改變水的特征",故本題答案為C選項.
70題答案:B考查主旨大意,本文主要講的是什么是納米材料及其目前的研究進展;故本題答案為B選項.
點評 本文是一篇科教類閱讀,題目涉及多道細節(jié)理解題,做題時結(jié)合原文和題目有針對 性找出相關(guān)語句進行仔細分析,結(jié)合選項選出正確答案.推理判斷也是要在抓住關(guān)鍵句子的基礎(chǔ)上合理的分析才能得出正確的答案.