[单选题]可路由网络协议的网络地址由哪两部分组成?( )[ 中]
A.网段地址和主机地址
B.主机地址和网络掩码
C.网段地址和网络掩码
D.网段地址和子网地址

The destruction of our natural resources and contamination of our food supply continue to occur, largely because of the extreme difficulty in affixing legal responsibility on those who continue to treat our environment with reckless abandon. Attempts to prevent pollution by legislation, economic incentives and friendly persuasion have been met by lawsuits, personal and industrial denial and long delays—not only in accepting responsibility, but more importantly, in doing something about it.
It seems that only when government decides it can afford tax incentives or production sacrifices is there any initiative for change. Where is industry’s and our recognition that protecting mankind’s great treasure is the single most important responsibility
If ever there will be time for environmental health professionals to come to the frontlines and provide leadership to solve environmental problems, that time is now. We are being asked, and, in fact, the pub
A. to prevent pollution by legislation, economic incentives and persuasion
B. to arouse public awareness of the importance of environmental protection
C. to take radical measures to control environmental pollution
D. to improve the quality of life by enforcing environmental standards