【单选题】“1831年法拉第发现电磁感应定律,1864年麦克斯韦建立电磁理论,1888年赫兹发现电磁波。这些发现,引发了发电机、电动机、电报、无线电的发明。”材料说明()
【简答题】《安全生产法》对生产经营单位的特种作业人员有何规定?
【单选题】根据《安全生产法》,生产经营单位的特种作业人员必须按照国家有关规定经专门的安全作业培训,取得______方可上岗作业。
【单选题】Now Berners-Lee is doing a new project which has nothing to do with the Internet.
【单选题】It can be inferred that a fashion shop should play______to attract customers.
A.
trendy and up-tempo music
D.
quick and lively music
【单选题】1831年,科学家( )发现了电磁感应定律。
【单选题】______the contrary,the rapid growth in enrollment over the last 40 years has come to an end.
【单选题】Our knowledge of the ocean has ___________ considerably over the last ten years.
【单选题】— He didn't go to bed last night until 12 o'clock last night. — Yes. He ______ his experiment over and over, working till midnight. [ ]