41●设集合N={0,1,2,…},f为从N到N的函数,且f(x)= f(f(+11) 0≤x≤90x-10 x>90经计算f(90)=81,f(89)=81,f(49)=__(62)__。
A.39
B.49
C.81
D.92
开始考试练习点击查看答案42●集合A={d.b.c}上的二元关系R为:R={<a,a>,<c,c>,<a,b>)},则二元关系R是__(63)__。
A.自反的
B.反自反的
C.对称的
D.传递的
开始考试练习点击查看答案43●对n个元素进行快速排序时,最坏情况下的时间复杂度为__(64)__。
A.O(1og2n)
B.O(n)
C.O(nlog2n)
D.0(n2)
开始考试练习点击查看答案44●任何一个基于“比较”的内部排序的算法,若对6今元素进行排序,则在最坏情况下所需的比较次数至少为__(65)__。
A.10
B.1l
C.21
D.36
开始考试练习点击查看答案45● SOCKS is a generic proxy protocol for ICP/IP-based networking , applications. SOCKS includes two __(66)__, the SOCKS server and the SOCKS client. The SOCKS server is implemented at the application layer. The SOCKS client is implemented between applications and the __(67)__ layer. When an application client needs to connect to an application server, the client connects to a SOCKS proxy server. The proxy server connects to the application server instead of. the client, and __(68)__ data between the client and the application server. For the application server, the proxy server is the __(69)__ . SOCKS is also one of the popular __(70)__ to network firewalls. Because of its simplicity and flexibility, SOCKS has been used as generic application proxy in virtual private network (VPN), and for extranet applications.
A.elements
B.components
C.services
D.ctients
开始考试练习点击查看答案46● A Web browser is simply a terminal emulator, designed to display text on a screen. The two essential differences between an ordinary terminal emulator and a Web browser are that the browser knows how to deal with __(71)__, and that it has a mechanism for __(72)__ graphical files. Display text, display graphics, and __(73)__ hyperlinks--there's 99 percent of the __(74)__ value. That's not to say that the manufacturers didn't go all-out to attach a hyperactive efflorescence of useless capabilities onto their browsers. Remember when media channels in the browser were a big deal, instead of the clutter you can't wait to delete from your favorites of bookmarks menu、 Remember when client-side Java applets were supposed to become the preferred __(75)__ for application development、 Remember frames and all their nasty side effects、
A.superlinks
B.links
C.hyperlinks
D.connections
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