去除铁锈的一般方法是（）

A、超声波清洗

B、机械清除

C、激光烧损

D、强酸浸泡

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) .

49（）

A.graphics 

B.processes 

C.scripts 

D.texts