12．There is no doubt that computers are very useful in technology and business．With the （86）hhelp of computers，doctors can find diseases easily and solve other problems．In factories，robots （87）control（l）ed（控制） by computers can do work that is dangerous to humans．In business，computers are used to place and cancel orders．They are also making the workplace （88）safer（安全） and better．
Since the Internet（89）came into being，people's lives at home have changed，too．More and more people have personal computers，（90）andthey use them to play games and watch movies．Instead of writing letters on paper，people communicate by sending e-mails and （91）chatting online．The whole world is connected．The Internet is making the world smaller，（92）like a village．
Computers have improved our lives．They have brought us （93）convenience（方便），but they have brought problems，too．For example，if we （94）eexpose ourselves to computers too long，we may get headaches or sore eyes．Besides，not everything we read on the Internet is true or good for us．Computers help us at work and at home，but they must be used （95）pproperly．
