A
Computer technology is still developing rapidly.The computer of the future will continue to increase in value and performance while decreasing in cost.It will become smaller, but faster and more powerful.
It is possible to make some guesses about what the future of the computer will look like，based upon the types of technologies that are being developed now.A lot of progress has already been made in some of these new technologies，but some are still in their earliest stages and may not be ready for use for years.Two of the most interesting areas of computing that are currently being developed are quantum computing (量子计算) and nanotechnology (纳米技术)．
Quantum computing is one possibility for the future of the computer that could make computers run far faster than even the quickest computers do today.Quantum computers could be able to do what modern supercomputers are unable to do by using transistors that are able to take on many states at the same time.
Nanotechnology could also change the face of computing，by creating computers that could be very powerful，though they are tiny in size.These computers could be incorporated (并入) into everyday objects, including electrical appliances (电器)，clothes and even the human body.We will be able to use computers in new and unimaginable ways.They will become a part of our lives rather than simply being a box that is used only for specific purposes，such as work.
Quantum computing and nanotechnology will be able to play new roles，which will make us live greener lives，as well as enjoy better health and happier lives.
文章大意：本文是一篇说明文。未来的计算机会采用量子计算和纳米技术，这样，它将会运行得更快、成本更低并且容量更大。
21．According to the text，quantum computing D.
A．has been put in use so far
B．can make computers run by themselves
C．can reduce the cost of computers
D．will work by using transistors
解析：细节理解题。根据第三段中的“Quantum computers could be able to do what modern supercomputers are unable to do by using transistors that are able to take on many states at the same time.”可知，量子计算机采用晶体管来工作。故选D项。
22．We can learn from the text that nanotechnology will A.
A．create much smaller computers
B．be used in electrical appliances and clothing
C．change the structure of computers
D．make computers just serve specific purposes
解析：细节理解题。根据第四段中的“Nanotechnology could also change the face of computing, by creating computers that could be very powerful，though they are tiny in size.”可知，纳米技术将会使未来的计算机变得更小。故选A项。
23．The text is mainly about C.
A．what nanotechnology is
B．what quantum computing is
C．what the future of the computer is
D．what future computers can bring us
解析：主旨大意题。第一段概括了文章的大意，即未来的计算机的发展。故选C。
