太空望远镜拍摄到了迄今为止最清晰的冥王星的照片。The space telescope has taken the clearest pictures ever of Pluto.天文学家知道冥王星与海卫一拥有几乎相同的体积、质量与密度。Astronomers know that Pluto and Triton have nearly the same size, mass, and density.冥王星似乎受到过严重撞击，倾斜了1...
The Earth orbits in an ellipse.地球轨道呈椭圆形。The man - made satellite orbits the earth every 48 hours.那颗人造卫星每48小时绕地球轨道运行一周.They knew each other by sight, but their orbits did not touch.他们见面认识, 但各自的生活圈子互不搭界....
They feel scared and powerless in conveyor-belt hospital wards.在千篇一律的病房里，他们感到恐惧而又无能为力。Raise one foot, curl the toes and point the foot down-wards.抬起一只脚，弯曲脚趾，使脚尖朝下。Toronto hospital maternity wards were filled to capacity....