Though "nanometer" 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 1000 micrometers,and one micrometer is 1000 nanometers.That is,one nanometer is one billionth of a meter.Nano materials are solid materials composed of particles or crystallites of less than 100 nanometer 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. Ji(director Institute of Nanomedicine): A water molecule is composed of 2 hydrogen atoms and 1 oxygen atom.It can be alterchanged only by special manipulation of the atoms.The material constituting the cup can have a nanometer particles size of the nano level.But it cannot change the chemical and physical properties of 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. Prof.Ji told the reporter,so far,the investigation of nano materials is still confined in the laboratory.No commercial micro products can be produced yet.With the present level of science and technology,the time of everyday goods age of daily use articles made of nanometer materials is still years away. The commodities labeled with nano marks in the market now are only traditional products coated with a thin layer of nanometer material,which makes them _ . Prof.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. Which of the following does not show that nano cups are different from ordinary cups?
Nano cups can't make people healthier. Nano cups are made of a different material. Nano cups are much easier to be cleaned. Nano cups are hard to produce.