At night, ships at sea carry a red light on the port side and a green light on the starboard. 夜晚,海上的船亮起左舷的红灯和右舷的绿灯。
Explorers in remote areas, ships at sea, even astronauts circling the earth axe able to keep in touch with civilization by means of radio. 到遥远地区探险的人们,在海上航行的轮船,甚至绕地球环行的宇航员们,都能借助无线电与有人居住的地方保持联系。