下面不是网络层的功能的是( )。
A.路由选择
B.流量控制
C.建立连接
D.分组和重组
参考答案:C
解析: 网络层的主要功能是路由选择、流量控制、分组和重组。
It still puzzles today's scientists _____ some mammals produce their young _____ others lay eggs to produce
their offspring (后代). [ ]
A. that; while
B. what; while
C. that; as
D. what; as
企业在异地开立的采购专户也可以进行款项的收付。( )