for a minute. You can't work hard all day.[ ]
A. Set up
B. Put up
C. Give up
D. Let up
答案:D
硅酸盐水泥熟料矿物水化时,凝结硬化速度最快的是()。
A.C2S
B.C3S
C.C4AF
D.C3A
整个EPON物理层由如下几个子层构成()
A.物理编码子层(PCS)
B.后向纠错子层(REC)
C.物理媒体附属子层(PMA)
D.物理媒体依赖子层(PMD)