在Excel工作表中，单元格引用的三种类型是：绝对引用、绝对行相对列引用、绝对列相对行引用。$E3是绝对列相对行引用。（）
参考答案：对
下图“画鬼从何取材”告诉我们
①人们的意识活动具有主动创造性
②世界的真正统一性在于其物质性
③意识是人脑特有的机能
④意识具有能动地改造世界的作用
A．①②
B．①③
C．①④
D．②④
Communication protocols are (66) connection-oriented or connectionless, (67) whether the sender of a message needs to contact and maintain a dialog with the recipient or (68) send a message without any, prior connect and with the hope that the recipient receives everything. (69) .These methods (70) the two ways that communication is implemented on networks.
A．make known
B．disclose
C．reveal
D．discover
