【单选题】By careful observation and precise calculation, Nicolaus Copernicus _____ that there is no one center in the universe and the sun is the center of the solar system. [ ]
【简答题】Health Education Health education is the part of health care that is concerned with promoting healthy behavior.A person’s behavior. may be the main cause of a health problem.but it can also be the mai...
【单选题】In the coordinate plane, points A and B are endpoints of a diameter of a circle with center ( -2,1). If the coordinates of A are ( -5,5) , what are the coordinates of B?