一、填空题(共24分,每空1分)1.在“信息高速公路”上,信息传播的速度等于真空中的光速,约为_____m/s;通过“信息高速公路”,上海接收到北京发出的信息,大约需要5×10-3s,则上海到北京的距离约为______km.2.我们在教室的各个方向都能看到黑板上的字,这是光的_____现象;而学习或工作用的台灯上有一个灯罩,其作用是利用光的_____规律将光线尽量集中到需要照射的地方,因此灯罩内表面应尽量 First, fill in the blank (a total of 24 points, 1 point per empty) 1. In the “information highway”, the speed of information dissemination is equal to the speed of light in the vacuum, about _____m / s; through the “information highway”, Shanghai received The information sent to Beijing needs about 5×10-3s, so the distance from Shanghai to Beijing is about ______km. 2. We can see the words on the blackboard in every direction of the classroom. This is the _____ phenomenon of light. And there is a lampshade on the desk lamp for study or work. Its function is to use the _____ law of light to concentrate the light to the place where it needs to be irradiated, so the inner surface of the lampshade should be as far as possible.