题型:单项选择题 An internet is a combination of networks connected by () .When a datagram goes from a source to a () ,it will probably pass many () until it reaches the router attached to the destination network.A router receives a () from a network and passes it to another network.A router is usually attached to several networks.When it receives a packet,to which network should it pass the packet The decision is based on optimization: Which of the available () is the optimum pathway.it will probably pass many () until it reaches the router attached to the destination network.A.destinationsB.routersC.packetsD.computers 查看答案
题型:选择题 托盘天平是科学实验中常用的仪器,下列关于其使用的说法中不正确的是A.称量物体前首先应估计被测物体的质量,以免超过量程B.称量物体前一定要把天平放在水平桌面,再将天平调平后才可以称量C.称量时,移动游码,相当于调节平衡螺母D.判断天平横梁是否平衡,不一定要等指针完全静止下来 查看答案
题型:单项选择题 请从下列名词中区分类和对象。其中, (1) 全部是类, (2) 全部是对象。1()A.电影、序列号为 sw1987532 的电影胶片、足球赛B.电影、足球赛、电影胶片C.影片“卡萨布兰卡”、足球赛D.影片“卡萨布兰卡”、序列号为 sw1987532 的电影胶片 查看答案