【简答题】天体是宇宙间物质的存在形式,宇宙间的天体因相互吸引、相互绕转而形成天体系统。读图,回答1~3题。 1.下列物质中,属于天体的有 ①太阳、月球、北斗七星 ②恒星、行星、卫星、彗星 ③火车、轮船、巨大岩石 ④待发射火箭、待发射宇宙飞船 [ ] A.①② B.③④ C.①③ D.②④ 2.图有几级天体系统 [ ] A.3 B.4 C.5 D.6 3.地球是中心天体的天体系统是 [ ...
【判断题】自动取证的文件分析中,可以对所找到的加密文件进行解密。
【单选题】She sometimes to school late.
【单选题】Although she has two daughters of her own, she sometimes has the sweetness and ______ of a child.
【简答题】A.She sometimes reads books. B.She has many things to do. C.She often goes shopping. D.She likes to visit friends.
【单选题】— Although she sometimes loses her temper, her students like her no less. — That’s it. _____ , she is really a good teacher.
【简答题】A.She intends to visit her friend in Texas. B.She sometimes travels abroad for her job. C.Her friend has never been to Texas before. D.She hasn't spoken to her friend for a long time.
【单选题】下列天体和天体系统中,具有从属关系,且从大到小依次排列的是( )
【单选题】下列有关天体和天体系统的说法正确的是
D.
任何两个天体都相互吸引、相互绕转而形成天体系统
【单选题】b .宇宙中的天体系统 ( )
A.
由天体之间的引力关系和相互运动而形成,北斗七星也是一个 天体系统
C.
总星系是目前已知的宇宙范围的全部,半径约 140 亿光年