Figure19.2以二进制和点分十进制标记法求类 First Second Third Fourth First Second Third Fourth byte byte byte byte byte byte byte byte Class A 0 Class A 0-127 Class B 10 Class B 128-191 Class C 110 Class C 192-223 Class D 1110 Class D 224-239 Class E 1111 Class E 240-255 a.Binary notation b.Dotted-decimal notation 19.819.8 Figure 19.2 以二进制和点分十进制标记法求类