噶尼喀湖位于中东部非洲，是一个非常古老的湖泊。该湖平均深度600m，唯一出口卢库加河呈淤塞甚至干涸的状态。该湖鱼类资源丰富，有数百种鱼为当地特有物种，尤其以品种众多、形态和行为多样的慈鲷鱼闻名于世。湖区周边国家经济落后。

    In the future，life will be much ____. Maybe there will be vision phones in every ____. People can have a medical examination without a ____ or nurse in the room and do some shopping without ____their homes. And what ____education? There will be ____educational programs on the radio or TV. So many children who live in far-away villages don't need to ____to school every day. They can study at home. Each family has a robot. Robots will ____ people do their housework. Perhaps some people will fly to the ____for a holiday and some people can live under the ____.

①骨骼肌收缩

②肌肉附着的骨受到牵拉产生动作

③骨骼肌接受神经传来的兴奋

④骨骼肌牵引骨绕着关节活动