题目

We are all busy talking about and using the Internet, but how many of us know the history of the Internet?Many people are surprised when they find that the Internet was set up in the 1960s. At that time, computers were large and expensive. Computer networks didn't work well. If one computer in the network broke down, then the whole network stopped. So a new network system had to be set up. It should be good enough to be used by many different computers. If part of the network was not working, information could be sent through another part. In this way computer network system would keep on work实验室常用质量分数为65%、密度为1.4g/cm3的浓硝酸配制稀硝酸，若要配制3mol/L的硝酸100mL，需要多少体积的这种浓硝酸？