I am sure that everybody in his/her life has used computers. Nowadays you can feel their presence everywhere at home，at school，at work and they certainly make life easier．On the other hand，there are people who can’t work with them．
Anyway，I believe their presence is a good thing. Life with them seems easier, less difficult and more comfortable You can use them to choose your meal，to withdraw your money, and also save your time，because these operations are all controlled by computers. Therefore you can hardly imagine the modern world without them；the whole planet seems to be one big computer society．
Nevertheless，problems can often appear in this area, too．To have a computer means you have to be quite well－off and have the necessary skills to use it．However，think about questions like “Are computers so available for everyone, or rich and poor people，for people from villages and people from cities. Aren’t they too expensive？Is everyone able to learn how to use them and not everyone has the chance to access and work with them，how could everything in the future be dependent on them？”Therefore，I think our society will be split into two parts．One part will work with them and enjoy the benefits that computers can bring and the other part will be pushed out and will actually be far behind the other group．
Another question that bothers me is，on the one hand，computers are important  and good things in our life，but they aren’t everything．They are good as a help at school，quite often as entertainment，especially for young people，as an necessary tool to help in research etc，but I think we shouldn’t be so dependent on them，because computers are only machines and machines can’t feel anything be human and sympathetic，and every action performed by computer can be interfered with another person，which could cause these machines to crash or work badly．
In conclusion，I would like to say I am not against computers．I use computers，too，but people should be wary all the time．
By saying “wary”（In the last paragraph）,the writer is trying to say “People should_______.

A．be strongly for the use of computers because of its convenience

B．be careful with computers that will also cause problems

C．master more necessary computer skills

D．not do something that causes computers to work badly

Which of the following best shows the structure of the passage？

In the third paragraph，the author presents his idea by________

A．asking questions for people to think about

B．giving examples to support his argument

C．raising questions and answering them

D．expressing his opinion directly

The writer’s main purpose in writing the passage is__________

A．to encourage us to use computers in our society

B．to advise us to say no to computers from now on

C．to remind us to care about the problems that computers bring.

D．to inform us that the computer has become a necessary part of our life