根据下面的文字资料回答 71～75 题In the following essay，each blank has fourchoices．Choose the best answer and write down on thean，swer sheet．

Microwave communication uses（ 1 ）frequency radio waves that travel instraighdine sthroughthe air．Because the waves cannot（ 2 ）with the curvature of the earth，they can be （ 3 ）onlyover short distance．Thus，microwave is a good（ 4 ）for sending data between bulldingsin a city or on a large college campus．For longer distances，the waves must berelayed by means of“dishes”or（ 5 ）．These can be installed on towers，highbuildings，and mountain tops．

第71题：文中（ 1 ）处正确的答案是（ ）。

A．high

B．10w

C．1ong

D．short

[单选题]根据下面的文字资料回答 71～75 题 n the following essay，each blank has four choices．Choose the most suitable one from the four choices and write down in the answer sheet．Open Shortest Path First(OSPF)is a（ 1 ）routing algorithm that（ 2 ）work done on the OSI IS-IS i

[单选题]根据下面的文字资料回答 71～75 题 In the following essay，each blank has four choices．Choose the most suitable one from the four choices and write down in the answer sheet．A（ 1 ）is basically an end point of a communication link between two applications.Sockets that

[单选题]根据下面的文字资料回答 71～75 题 In the following essay．each blank has four choices．Choose the best answer and write down on the answer sheet．Spread spectrum simply means that data is sent in（ 1 ）pieces over a number of the discrete frequencies available for use

[单选题]根据下面的文字资料回答 71～75 题 The purpose of the requirements definition phase is to produce a clear,complete，consistent，and testable（ 1 ）of the technical requirements for the software produet．D．uring the requirements definition phase，the requirements deftnifi

[单选题]根据下面的文字资料回答 71～75 题 connected by（ 1 ）or Hubs,which just move the bits from one network to an identical network. One layer up we find bridgas and swiehes,which operate at data link layer. They can accept （ 2 ） , examine the MAC address, and forward th

[单选题]根据下面的文字资料回答 71～75 题 The Simple Network Management Protocol(SNMP)is an （ 1 ）protocol that facilitates the exchange of management information between （ 2 ）．It is part of the Transmission Control ProtocoL/Internet Protocol(TCP/IP)protocol suite. SNMP en

[单选题]根据下面的文字资料回答 71～75 题。2007年6月1日，A市李某从国外进口一批货物，经过B市海关，因货物被怀疑走私而被B市海关扣押并拟处罚款10000元。并于当日告知李某有要求举行听证的权利。根据案情回答下列题目：第 71 题 若海关最终决定对李某处以罚款，则（ ）。A．海关扣押了李某的货物，并且对李某处以罚款的行政处罚，违反了一事不二罚的原则B．李某对扣押的行政处罚不服的，必须先提起行政复议 。C．海关未告知李某对扣押货物的行为享有申请听证的权利，违反了法定程序，该行为 无效D．扣押和罚款

[单选题]根据下面的文字资料回答 63～67 题In low-speed network，it is usually adequate to wait for congestion to occur andthen react to it by telling the source of packets to slow down．In high-speednetworks，this approach oftenworks poorly，because in the（ 1 ）between sending

[单选题]根据下面的文字资料回答 66～70 题In low-speed network，it is usually adequate to wait for congestion to occur andthen react to it by telling the source of packets to slow down．In high-speednetworks，this approach oftenworks poorly，because in the（ 1 ）between sending

[单选题]根据下面的文字资料回答 68～72 题For each blank．choose the best answerfrom the four choices and write down on the answer sheet．（ 1 ）is a protocol that a host uses toinform. a router when it joins or leaves an Internet muhicast group．（ 2 ） is an error detection cod