网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
【单选题】Lesson 15 词汇拓展-词汇选择-10 ADSB broadcasts aircraft position and other relevant information to air traffic controllers over several dedicated datalink technologies which are simply different ________used by the equipment to transmit and receive.
A．channels
B．frequencies
C．protocols
D．stations
参考答案和解析
originated
更多 “【单选题】Lesson 15 词汇拓展-词汇选择-10 ADSB broadcasts aircraft position and other relevant information to air traffic controllers over several dedicated datalink technologies which are simply different ________used by the equipment to transmit and receive.A．channelsB．frequenciesC．protocolsD．stations” 相关考题
考题
Telecommunications stand for devices and systems that transmit electronic or optical signals across long distances. Telecommunications enables people around the world to contact one another, to access information instantly, and to communicate from remote areas. Telecommunications usually involves a sender of information and one or more recipients linked by a technology, such as a telephone system, that transmits information from one place to another. Telecommunications enables people to sand and receive personal messages across town, between countries, and to and from outer space. It also provides the key medium for delivering news, data, information, and entertainment.Telecommunications devices convert different types of information, such as sound and video, into electronic or optical signals. Electronic signals typically travel along a medium such as copper wire or are carried over the air as radio waves. Optical signals typically travel along a medium such as strands of glass fibers. When a signal reaches its destination, the device on the receiving end converts the signal back into an understandable message, such as sound over a telephone, moving images on a television, or words and pictures on a computer screen.Telecommunications messages can be sent in a variety of ways and by a wide range of devices. The messages can be seat from one sender to a single receiver (point-to-point) or from one sender to many receivers (point-to-multipoint). Personal communications, such as a telephone conversation between two people or a facsimile (fax) message (see Facsimile Transmission), usually involve point-to-point transmission. Point-to-multipoint telecommunications, often called broadcasts, provide the basis for commercial radio and television programming.Telecommunications begin with messages that are converted into electronic or optical signals. Some signals, such as those that carry voice or music, are created in an analog or wave format, but may be converted into a digital or mathematical format for faster and more efficient transmission. The signals are then sent over a medium to a receiver, where they are decoded back into a form. that the person receiving the message can understand. There are a variety of ways to create and decode signals, and many different ways to transmit signals.Individual people, businesses, and governments use many different types of telecommunications systems. Some systems, such as the telephone system, use a network of cables, wires, and switching stations for point-to-point communication. Other systems, such as radio and television, broadcast radio signals over the air that can be received by anyone who has a device to receive them. Some systems make use of several types of media to complete a transmission. For example, a telephone call may travel by means of copper wire, fiber-optic cable, and radio waves as the call is sent from sender to receiver. All telecommunications systems are constantly evolving as telecommunications technology improves. Many recent improvements, for example, offer high-speed broadband connections that are needed to send multimedia information over the Internet.Personal computers have pushed the limits of the telephone system as more and more complex computer messages are being sent over telephone lines, and at rapidly increasing speeds. This need for speed has encouraged the development of digital transmission technology. The growing use of personal computers for telecommunications has increased the need for innovations in fiber-optic technology.Telecommunications and information technologies are merging and converging. This means that many of the devices now associated with only one function may evolve into more versatile equipment. This convergence is already happening in various fields. Some telephones and pagers are able to store not only phone numbers but also names and personal information aboA．Current development.B．Transmission of message.C．Computer networking.D．Government regulation.
考题
Which of the following correctly describe characteristics of PPP?()
A. Encapsulates several different types of routing protocols.B. Supports only IP.C. Can be used over analog circuits.D. Is proprietary to CiscoE. Supports error correction.
考题
The ladder shall ______．A.be secured in a position so that it rests firmly against the ship's side from which the discharge operations are carried outB.have at least two replacement steps which are secured in position by a method different from that used in the original constructionC.have battens made of hardwood，or other material of equivalent properties，in one piece and not less thanD.have steps made of softwood，or other material of equivalent properties，made in one piece free of knots，having an efficient slip surface
考题
In June 1956 a TWA Constellation collided with a United Air Lines DC-7 over the Grand Canyon in Arizona,killing all 128 people on both aircraft.At the time it was the worst ever airline disaster Struggling with outdated technology and a post-war boom in air travel overworked air-traffic controllers failed to spot that the planes were on a collision course.（1）With that system again struggling to keep pace with demand,Donald Trump thinks it is time to privatise Americas air-traffic control service.This week the president out-lined a plan to turn air-traffic control into a separate non-profit entity financed by user fees,instead of the present patchwork of taxes and grants.Shorn of its air-traffic responsibility,the FAA would become a satety body America's air-traffic system is vast,consising of 14,000 controllers working in 476 airport-control towers that handle take-offs and landings,as well as in 21"en route"centres looking after flights along the nation's airways.（2）This leads to delays and frustrated flyers.With passenger numbers set to grow from 800m a year to almost Ibn by 2026,the problem will only get worse（3）Many countries,including Australia,Britain and Canada,have privatised air-traffic services or turned them into state-owned firms.Nav Canada,a non-profit firm that has long managed Canadian airspace,has costs per flight hour of 340 compared with the FAA's$450.Replacing old radar-based methods with accurate satellite navigation and better digital communications is a particular priority.Aircraft using satellite navigation can be safely spaced more closely together,which permits many more planes to be in the air at the same time.Digital systems also provide data links to control centres and to other planes by regularly broadcasting an aircraft's identification sign,its position and course.（4）The president's proposal might even speed a move towards"virtual"control towers in low-rise buildings,which can replace towers physically localed at airports.The European Union reckons such innovations will allow three times as many flights to be handled in the region and save airlines some 9bn（$10bn）a year.It also,optimistically perhaps,predicts that on average aircraft will land with in one minute of their scheduled arrival time.That would count as a miraculous improvement for any one,let alone America's weary airport warriors（5）A similar plan got stuck last year,despite being backed by most airlines and the air-traffic controllers'union.At least the president can dodge the queues Air Force One flights get special clearance
4选？A.In addition to providing air traffic services,the FAA also provides safety oversight for those services,which may create an inherent conflict of interest
B.It has a good safety record,but elderly technology limits the number of flights that can be haned
C.Many Democrats argue that changing the status quo is unnecessary given that flying in the United States is as safe as it's ever been
D.Mr Trump believes that,no longer mired in a federal bureaucracy the air-traffic service will become more efficient and better able to invest in technology
E.This would allow"free routing",which means pilots can fly diretly to a destination,rather than fllow established aiways,which often zigzag around.
F.Mr Tump.though,may struggle to get the proposal through Congress.
G.That crash led to the creation of a new body,which became the Federal Aviation Administration（FAA）,in charge of running and modermising the world's biggest air-transport system.
考题
The term computer describes a device made up of a combination of electronic components．By itself, a computer has no ( ) and is referred to as hardware, which means simply the physical equipment． The hardware can't be used until it is connected to other elements, all of which constitute the six parts of a computer-based information system,hardware,software,data/information, people, procedures and communications．
A system is defined as a collection of related components that ( ) to perform a task in order to accomplish a goal． Any organization that uses information technology will have a computer-based information system to provide managers (and various categories of employees with the appropriate kind of information to help them make decisions．
Systems analysis and design is to ascertain how a system works and then take steps to make it ( ) Often, a system approach is used to define, describe, and solve a problem or to meet a(an)（ ）
From time to time, organizations need to (5 ) their information systems, in, response to new marketing' opportunities, modified government regulations, the introduction ．of new technology, merger with another company, or other developments． When change is needed, the time is ripe for applying the principles of systems analysis and design．
（5）应选（ ）。
A. modify
B. replace
C. Change
D. transfer
考题
The term computer describes a device made up of a combination of electronic components．By itself, a computer has no ( ) and is referred to as hardware, which means simply the physical equipment． The hardware can't be used until it is connected to other elements, all of which constitute the six parts of a computer-based information system,hardware,software,data/information, people, procedures and communications．A system is defined as a collection of related components that (请作答此空) to perform a task in order to accomplish a goal． Any organization that uses information technology will have a computer-based information system to provide managers (and various categories of employees with the appropriate kind of information to help them make decisions．Systems analysis and design is to ascertain how a system works and then take steps to make it ( ) Often, a system approach is used to define, describe, and solve a problem or to meet a(an)（ ）From time to time, organizations need to ( )their information systems, in, responseto new marketing' opportunities, modified government regulations, the introduction ．of new technology, merger with another company, or other developments． When change is needed, the time is ripe for applying the principles of systems analysis and design．A.interact
B.work
C.connect
D.change
考题
Designing the data storage architecture is an important activity in system design. There are two main types of data storage formats： files and databases. Files are electronic of data that have been optimized to perform a particular transaction. There are several types of files that differ in the way they are used to support an application. （请作答此空） store core information that is important to the business and , more specifically , to the application , such as order information or customer mailing information. （ ） contain static values , such as a list of valid codes or the names of cities . Typically, the list is used for validation. A database is a collection of groupings of information that are related to each other in some way. There are many different types of databases that exist on the market today. （ ） is given to those databases which are based on older , sometimes outdated technology that is seldom used to develop new applications . （ ） are collections of records that are related to each other through pointers In relational database , （ ） can be used in ensuring that values linking the tables together through the primary and foreign keys are valid and correctly synchronized.A. Master files
B. Look-up files
C. Transaction files
D. History files
考题
Designing the data storage architecture is an important activity in system design. There are two main types of data storage formats： files and databases. Files are electronic of data that have been optimized to perform a particular transaction. There are several types of files that differ in the way they are used to support an application. （ ） store core information that is important to the business and , more specifically , to the application , such as order information or customer mailing information. （ ） contain static values , such as a list of valid codes or the names of cities . Typically, the list is used for validation. A database is a collection of groupings of information that are related to each other in some way. There are many different types of databases that exist on the market today. （ ） is given to those databases which are based on older , sometimes outdated technology that is seldom used to develop new applications . （ ） are collections of records that are related to each other through pointers In relational database , （请作答此空） can be used in ensuring that values linking the tables together through the primary and foreign keys are valid and correctly synchronized.A. identifying relationships
B. normalization
C. referential integrity
D. store procedure
考题
Why does L4TM require T1 to be in promiscuous mode？（） A、to process traffic that is not intended for its MAC addressB、to transmit TCP reset packetsC、to bind with other promiscuous mode portsD、to receive Ethernet broadcasts
考题
Which of the following BEST describes a hub?（）A、Determines the best route to transmit dataB、Inspects traffic and accepts or declines transmissionC、Broadcasts data to specific network devicesD、Broadcasts data to all network devices
考题
If voice and data traffic will be sent and received via a WAN links， what must be configured to provide a certain amount of dedicated bandwidth and to prioritize the voice traffic over other types of network traffic？（）A、IPSec VPNB、QoS mechanismC、FirewallD、NATE、EIGRP routing protocolF、Static routing
考题
In optical channel transport unit overhead （OTU OH）， what are general communication channels 1 and 2（GCC1/GCC2） used for？（）A、for trail trace identificationB、as the backward defect indicatorC、to transmit information between OTU termination pointsD、to extend command and management functions over several framesE、General communication channels 1 and 2 （GCC1/GCC2） do not belong to OTU OH
考题
Which statements are true regarding ISDN channels?（）A、Each B channel can transmit up to 64 kbpsB、The ISDN B channel carries voice or dataC、The ISDN D channel transmits control information.D、The D channel transmission rate varies depending on the service used.E、HDLC or PPP can be used to encapsulate D channel information.
考题
Which of the following protocols define the rules and processes used to transmit and receive block storage applications over TCP/IP？（）A、iSCSIB、VoIPC、Distributed Applications over IPD、HTTPS
考题
单选题If voice and data traffic will be sent and received via a WAN links， what must be configured to provide a certain amount of dedicated bandwidth and to prioritize the voice traffic over other types of network traffic？（）A
IPSec VPNB
QoS mechanismC
FirewallD
NATE
EIGRP routing protocolF
Static routing
考题
单选题（）is used for receiving maritime safety information which is automatically printed by the receiver.A
NAVETEX receiverB
Search and Rescue TransponderC
Emergency Position Indicating Radio BeaconD
Digital selective calling
考题
单选题Why does L4TM require T1 to be in promiscuous mode？（）A
to process traffic that is not intended for its MAC addressB
to transmit TCP reset packetsC
to bind with other promiscuous mode portsD
to receive Ethernet broadcasts
考题
单选题（） is a circular traffic lane used at junctions of several routes，within which traffic moves counterclockwise around a separation point or zone.A
Traffic LaneB
RoundaboutC
Inshore Traffic ZoneD
Two-way Route
考题
多选题Which of the following correctly describe characteristics of PPP?（）AEncapsulates several different types of routing protocols.BSupports only IP.CCan be used over analog circuits.DIs proprietary to CiscoESupports error correction.
考题
单选题All the following equipment can be used to identify the position of the vessel in distress except（）.A
AISB
LRITC
VDRD
GPS
考题
单选题In optical channel transport unit overhead （OTU OH）， what are general communication channels 1 and 2（GCC1/GCC2） used for？（）A
for trail trace identificationB
as the backward defect indicatorC
to transmit information between OTU termination pointsD
to extend command and management functions over several framesE
General communication channels 1 and 2 （GCC1/GCC2） do not belong to OTU OH
考题
单选题As a result of sophisticated technologies, this device has several advantages over like products.A
traditionalB
intelligentC
industriousD
advanced
考题
单选题Which of the following protocols define the rules and processes used to transmit and receive block storage applications over TCP/IP？（）A
iSCSIB
VoIPC
Distributed Applications over IPD
HTTPS
考题
单选题Which of the following statements is TRUE regarding automatic identification systems (AIS)? （）A
AIS is a short-range VHF-FM system that automatically broadcasts a vessel's position，course，speed and other safety related information to all those with similar equipment in the areaB
AIS is a one-way centrally managed system that requires the local VTS to send commands to instruct each vessel to broadcast position，course，speed and other safety related information to all those with similar equipment in the areaC
AIS is a global tracking system that relies upon INMARSAT C service to communicate vessel position，course，speed and other safety related information to all those with similar equipment in the areaD
AIS is a short-range 3 cm X-band radar system that automatically sends a vessel's position，course，speed and other safety related information to all those with similar equipment within the area
考题
多选题Which three statements about NetFlow are true？（）ANetFlow records unidirectional IP traffic flow.BNetFlow records MPLS frame flow.CNetFlow expert is only over TCP.DNetFlow records is only over UDP.ENetFlow records subinterface information of traffic flow.
考题
单选题Which of the following statements is TRUE regarding automatic identification systems (AIS)? （）A
AIS is a global tracking system that relies upon INMARSAT C service to communicate vessel position and other safety related information to similarly equipped vessels，aircraft and shore stations within the areaB
AIS is a short-range 3 cm X-band radar system that automatically sends a vessel's position and other safety related information to similarly equipped vessels，aircraft and shore stations within the areaC
AIS is a short-range VHF-FM system that automatically broadcasts a vessel's position and other safety related information frequently to similarly equipped vessels，aircraft and shore stations within the areaD
AIS is a one-way centrally managed system that requires the local VTS to send commands to instruct each vessel to broadcast position and other safety related information to similarly equipped vessels，aircraft and shore stations within the area
考题
单选题If an air compressor is used to supply air primarily to the combustion control system and other pneumatic controllers, the entire system is known as the （）.A
control air systemB
forced draft air systemC
supply air systemD
ships service air system
考题
单选题The ladder shall（）.A
be secured in a position so that it rests firmly against the ship's side from which the discharge operations are carried outB
have at least two replacement steps which are secured in position by a method different from that used in the original constructionC
have battens made of hardwood，or other material of equivalent properties，in one piece and not less than 1.80metres long provided at such intervals as will prevent the pilot ladder from twistingD
have steps made of softwood，or other material of equivalent properties，made in one piece free of knots，having an efficient slip surface
热门标签
最新试卷