分类：教育/科学-外语学习-英语考试
问题：选择1.Haveyouanyidea()?A.thatlight 
1.Have you any idea(  )?A.that light travels how fastB.how does light tarvel fast.how fast does light travelD.how fast light travels
回答：这题选D.
Have you any idea how fast light travels?
你知道光速有多快吗？