单项选择题 Circuit-switching technology is used in Publish Switched Telephone Network(PSTN), Global System for Mobile Communications(GSM) and code Division Multiple Access (CMDA) . It is a ( ) information transfer mode.

单项选择题 Information theory is related to the quantification of information. This was developed by Claude E. Shannon to who found fundamental limits on ( ) operations such as compressing data and on reliably storing and communicating data.

单项选择题 某项目的项目经理在进行项目范围变更时,在对项目的技术和管理文件做了必要的修改后，他下一步应该（）。