32) What is the sequence number in a TCP header used for (在T C P报头中的顺序号的作用
是什么)？
A. Acknowledgments
B. Reordering of the octets received
C. Rejecting duplicate octets
33) Variable sliding windows provide an explicit mechanism for notifying TCP if an intermediate node (for example, a router) becomes congested (在中间节点，例如一个路由器拥
塞的情况下，可变滑动窗口提供了通知T C P的显式机制)。
A. True
B. False
34) Which of the following parameters is not a part of UDP header (下面的哪一个参数不是U D P报头的一部分)？
A. Source port
B. Urgent pointer
C. Checksum
D. Length
E. Destination port
35) When a router has been configured for UDP flooding, the source address might change,but the destination address will not change as the datagram propagates through the network (当一个路由器已经配置为U D P泛洪时，当数据报在网络上传播的过程中，源地址可能改变，但是目的地址不会改变)？
A. True
B. False
36) The spanning-tree algorithm allows (生成树算法允许)：
A. Forwarding of packets with no control
B. Forwarding of broadcasts to an interface which already has received the broadcast
C. Prevention of duplication of forwarding of packets
D. A and B only
37) IP helper addresses are a form of _ _ _ _ _ _ _ _ _ _ _ _ _ _ addressing and require the command specification of _ _ _ _ _ _ _ _ _on every interface receiving broadcasts that need to be forwarded (IP辅助地址是一种什么类型的寻址方法，在每一个接收到需要转发的广播接口上需要什么命令说明)？
