单项选择题
A．walk just as they do on the earth B．not eat anything because it’ s dangerous C．control the spaceship when they are sleeping D．not litter small things or it will make trouble
A．demanding greater freedom to go wherever they please B．making decisions without parental interference C．getting married whenever they please D．doing what they please
A．a medical operation B．a medical needle C．a medical technique D．a medical machine