Since the 1970s, scientists have been searching for ways to connect the brain with computers. Braincomputer interface(BCI) technology could help people with disabilities send commands to machines.
    Recently, two scientists, Jose Millan and Michele Tavella from the Federal Polytehnic School in Lausanne, Switzerland, show a small robotic wheelchair directed by a person's thoughts.
    In the laboratory, Tavella operated the wheelchair just by thinking about moving his left or right hand. He could even talk as he watched the vehicle and guided it with his thoughts.
    “Our brain has billions of body cells(细胞). These send signals through the spinal cord(脊髓) to the body part to give us the ability to move. But spinal cord injuries(脊柱受伤) or other conditions can prevent these weak electrical signals from reaching the body part.” Tavella says. “Our system allows disabled people to communicate with outer world and also to control machines.”
    The scientists designed a special cap for the user. This head cover picks up the signals from the scalp(头皮) and sends them to a computer. The computer finds meanings of the signals and commands the wheelchair with an engine. The wheelchair also has two cameras that tell objects in its path. They help the computer react to commands from the brain.
    Prof. Millan , the team leader, says scientists keep improving the computer software that finds meanings of brain signals and turns them into simple commands.” The practical possibilities that BCI technology offers to disabled people can be grouped in two kinds: communication, and controlling objects. One example is this wheelchair.”
    He says his team has set two goals. One is testing with real patients, so as to prove that this is a technology they can get advantages from. And the other is sure that they can use the technology for long.

党的十七大以来，我国社会生产力和综合国力显著提高，人民生活水平和社会保障水平显著提高，国际地位和国际影响力显著提高。国内生产总值从26.6万亿元增加到51.9万亿元，跃升到世界第二位。由此，对我国国情可以这样认为（   ）
①我国已进入高收入国家行列               ②我国现在仍处于社会主义初级阶段 
③我国仍是世界最大发展中国家           ④我国社会的主要矛盾已得到根本解决 

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