You'll probably never go to Mars or sing on the stage with The Rolling Stones. But if virtual reality （VR）ever lives up to its promise, you might be able to do all these things - and many more - without even leaving your home.Unlike real reality, virtual reality means simulating（模拟）bits of our world. Apart from games and entertainment, it's long been used for training airline pilots and surgeons and for helping scientists to figure out difficult problems such as the structure of protein molecules（蛋白质分子）. Then how does it work?

Close your eyes and think of virtual reality and you probably picture something like this:a man wearing a wrap-around headset and data gloves wired into a powerful workstation or supercomputer. What distinguishes VR from an ordinary computer experiences the nature of the input and output. While an ordinary computer uses things like a keyboard, a mouse, or speech recognition for input, VR uses sensors that detect how your body is moving. A PC displays output on a screen while VR uses two screens （one for each eye） , surround-sound speakers, and maybe some forms of touch and body feedback as well.

VR has been routinely used by scientists,doctors, engineers, architects, archaeologists, and the military for about the last 30 years. Difficult and dangerous jobs are hard to train for. How  can you safely practice taking a trip to space, making a parachute jump, or carrying out brain surgery? All these things are obvious candidates for virtual reality applications.

Like any technology, virtual reality has both good and bad points. Critics always raise the risk that people may be addicted to alternative realities to the point of ignoring their real-world lives, but this criticism has been leveled at everything from radio and TV to computer games and the Internet. Like many technologies, VR takes little or nothing away from the real world: you don't have to use it if you don't want to.

【小题1】According to the passage, virtual reality means ____________ .

A．imagining beautiful things in our mind

B．creating something that doesn't exist

C．creating an environment that seems real

D．cloning something that has died out

【小题2】What equipment do we probably need for virtual reality?

A．A keyboard, a headset and a supercomputer.

B．A headset, data gloves and speech recognition.

C．A headset, data gloves and a supercomputer.

D．A keyboard, a mouse and speech recognition.

【小题3】Paragraph 3 is mainly about ____________ .

A．the principles of virtual reality

B．the applications of virtual reality

C．the history of virtual reality

D．the study team of virtual reality

【小题4】What is the writer's attitude towards VR?

A．Appreciative.	B．Cautious.
C．Skeptical.	D．Indifferent.

短文改错
Dear Linda,

I've learned that you’re having much trouble with your life and study, which seriously affected your happiness. I'm worried about that, but I'm writing to share some of my ideas with you.

First of all, it is good to have heart-to-heart talks with your parents regular, telling them you won't fail us. Meanwhile, you had better tell them not to pushing you too hard, which will lead too much anxiety.Beside, it is advisable to spare some time to take some exercises to keep healthy. That is the most important is that we should always keep optimistic and confident.

Please take my advice into the consideration.

Yours,

Li Hua