VOA慢速英语:科学家扫描1000颗恒星 未发现任何生命迹象

alien -- n. from somewhere other than the planet Earth

indication – n. something (such as a sign or signal) that points out or shows something

galaxy – n. astronomy any one of the very large groups of stars that make up the universe

evaluation – n. to judge the value or condition of (someone or something) in a careful and thoughtful way