单项选择题
Originally introduced by Netscape Communications, (48) are a general mechanism which HTTP Server side applications, such as CGI (49) , can use to both store and retrieve information on the HTTP (50) side of the connection. Basically, Cookies can be used to compensate for the (51) nature of HTTE The addition of a simple, persistent, client-side state significantly extends the capabilities of WWW-based (52) .
51（）
A.fixed B.flexible C.stable D.stateless
单项选择题 4（）
单项选择题 1（）
单项选择题 在JPEG的基于DCT的基本系统中使用的AC系数行程编码的码字，共使用两个字节表示，其中第2个字节存放的是（）。
