Imagine this：A television screen has the size and thickness of a piece of paper．You carry it around in your pocket and take it out when you want to watch a show．Imagine a guitar so tiny that you can’t see it with the human eye，but you can hear sound when its strings（弦）are pulled．

Nanotechnology is the science that deals with doing things in a very small way, and it is being studied and developed all over the world．Many scientists say nanotechnology will produce the next industrial revolution（工業(yè)革命）．

Perhaps nanotechnology will have the biggest influence on medical science．Imagine nanobots（納米機(jī)器人）in medicine．Thousands or even millions of tiny machines can he sent into the human body with different tasks．For example，they can be designed（設(shè)計(jì)）to find and kill cancer cells or viruses（病毒）．Other machines may stay in the human body for ever to help organs（器官）that are not working properly．

When could all of these happen? Scientists believe that most of these are possible in the next 30 years. Thousands of scientists around the world are working on these micro-machines．Nanotechnology is just around the corner．

1．How did the writer introduce the topic（引出話題）of the passage?

2．What is nanotechnology?

3．What does the underlined word they refer to in the third paragraph?

4．What do many scientists think of nanotechnology?

5．Will all the micro-machines be possible in the next 30 years according to scientists?

Imagine this：a television screen has the size and thickness of a piece of paper．You carry it around in your pocket and take it out when you want to watch a show．Imagine a guitar so tiny that you can’t see it with the human eye，but you can hear sound when its strings are pulled．

Nanotechnology(納米技術(shù)) is the science that deals with doing things in a very small way, and it is being studied and developed all over the world ．Many scientists say nanotechnology will produce the next industrial revolution(工業(yè)革命) ．

Perhaps nanotechnology will have the biggest influence on medical science．Imagine nanobots(納米機(jī)器人)in medicine．Thousands or even millions of tiny machines can be sent into the human body with specific tasks．For example, they can be designed to find and destroy cancer cells or viruses(病毒) ．Other machines may stay in the human body for ever to help organs(器官) that are not working properly．

When could all of these happen? Scientists predict that most of these are possible in the next 30 years．Thousands of scientists around the world are working on these micro-machines ．Nanotechnology is just around the corner．

1．The two examples in Paragraph 1 are used to _______．

    A．introduce the smallest television

    B．introduce a new kind of guitar

    C．introduce the topic of the passage

    D．show how small the world is

2．Nanotechnology_________．

    A．will cause an industrial revolution

    B．deals with things in old ways

    C．has studied the whole world

    D．was developed many years ago

3．The underlined world“they”in the third paragraph refers to(指代)“________”．

    A．scientists      B．human bodies         C．specific tasks       D．tiny machines

4．The tiny machines __________．

    A．a(chǎn)re too small to be repaired

    B．call be put in a human body to kill viruses

    C．may not work well in a human body

    D．can take the place of human organs

5．The underlined phrase“around the corner”in the last sentence mans“________”．

    A．far away       B．a(chǎn)t present      C．in the near future          D．impossible