第1题：
The Ezonexam LAN is upgrading all devices to operate in full duplex. Which statement is true about full-duplex Ethernet in comparison to half-duplex Ethernet?
A．Full-duplex Ethernet uses two wires to send and receive. Half-duplex Ethernet uses one wire to send and receive
B．Full-duplex Ethernet consists of a shared cable segment. Half-duplex Ethernet provides a point-to-point link
C．Full-duplex Ethernet can provide higher throughout than can half-duplex Ethernet of the same bandwidth
D．Full-duplex Ethernet uses a loopback circuit to detect collisions. Half-duplex ethernet uses a jam signal
E．None of the above
第2题：
When you compare the differences between half-duplex and full-duplex Ethernet, which of the following characteristics are exclusive to half-duplex? (Select two answer choices)
A．Half-duplex Ethernet operates in a shared collision domain.
B．Half-duplex Ethernet operates in an exclusive broadcast domain.
C．Half-duplex Ethernet has efficient throughput.
D．Half-duplex Ethernet has lower effective throughput.
E．Half-duplex Ethernet operates in an exclusive collision domain.
第3题：
【An overall cellular network contains a number of different elements from the base transceiver station (BTS) itself with its antenna back through a base station controller (BSC), and a mobile switching centre (MSC) to the location registers (HLR and VLR) and the link to the public switched telephone network (PSTN). Of the units within the cellular network, the BTS provides the direct communication with the mobile phones. There may be a small number of base stations then linked to a base station controller. This unit acts as a small centre to route calls to the required base station, and it also makes some decisions about which of the base station is best suited to a particular call. The links between the BTS and the BSC may use either land lines of even microwave links. Often the BTS antenna towers also support a small microwave dish antenna used for the link to the BSC. The BSC is often co-located with a BTS. The BSC interfaces with the mobile switching centre. This makes more widespread choices about the routing of calls and interfaces to the land line based PSTN as well as the HLR and VLR.】 From the paragraph above, in a cellular network, the （98） can provide direct communication with a mobile phone, the （99） acts as a small centre to route calls to the required base station, and it also makes some decisions about which of the base station is best suited to a particular call.（100） can be used to link the BSC with related BTS。
A. BSC B. BTS C. MSC D. VLR A. BSC B. BTS C. MSC D. HLR A. Land lines B. Microwave links C. Microwave dish antenna D. Land lines or microwave links
第4题：
______ is a contiguous, numbered set of variables of a given base type, which can be used and passed to functions as a unit.
A．Record
B．Array
C．File
D．Parameter
第5题：
Which of the following statements correctly describe the differences between half-duplex and full-duplex Ethernet? (Select two answer choices.)
A．Full-duplex Ethernet uses CSMA/CD to prevent collisions.
B．Half-duplex Ethernet uses a loopback circuit to detect collisions.
C．A full-duplex Ethernet card allows 20Mbps for data transmission.
D．Full-duplex Ethernet makes use of two pairs of wires for data.
E．An Ethernet hub can operate both half and full duplex simultaneously.
第6题：
The maximum data rate of any single wireless link can be described by the shannon’s theorem which is related to the（）in hertz，and the（）on the channel
A．signal frequency B．bandwidth C．carrier frequency D．noise frequency A．signal B．caeeier C．noise D．data signal
第7题：
A.two year and a half
B.two years and a half
C.two and half a years
D.two and half a year
第8题：
You want to upgrade the Ezonexam LAN so that all ports operate in full duplex mode. Which statement is true about full-duplex Ethernet when comparing to half-duplex Ethernet?
A．Full-duplex Ethernet consists of a shared cable segment. Half-duplex provides a point-to-point link
B．Full-duplex Ethernet uses two wires to send and receive. Half-duplex Ethernet uses one wire to send and receive
C．Full-duplex Ethernet can provide higher throughput than can half-duplex Ethernet of the same bandwidth
D．Full-duplex Ethernet uses a loopback circuit to detect collisions. Half-duplex Ethernet uses a jam signal
E．None of the above
第9题：
For a continuous operation diesel engine, a duplex filter unit would be the best arrangement because
A.changing filter elements would not interrupt engine operation
B.filtering occurs twice in each pass of oil through the system
C.clogging will not occur
D.dropping pressure is half of that through a single filter unit
第10题：
Bluetooth is a universal radio interface in the(71)frequency hand that enables portable electronic devices to connect and communicate wirelessly via short-range, ad hoc networks. Each unit can simultaneously communicate with up to(72)other units per piconet. Moreover, each unit can simultaneously(73)to several piconets. Eliminates the need for wires, cables and connectors for and between cordless or mobile phones, modems, headsets, PDAs, Computers, printers, projectors, local area networks, and so on, and paves the way for new and completely different devices and applications. Technology Characteristics(74)symbol rate exploits maximum available(75)bandwidth。
A．1.95GHz
B．2.45GHz
C．4.45GHz
D．11.45GHz