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 wor一位古生物学研究一个未受干扰的岩石层中化石后,鉴定出一个物种,他认为这个物种在一个较长的历史年代中没有发生什么变化,因为他发现 [  ] A.该物种化石出现在较老岩层中 B.该化石出现在较新的岩层中 C.该化石在岩层中出现中断 D.该物种化石出现在较老和较新的岩石层中
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