
Each 8 bit unit used to code data is called a byte.()

第1题
A.Erlang
B.Bit/second
C.Hertz
D.Subscribers/kHz
E.Subscribers/minute
第2题
ace level (i.e. the complement of a mark) for one element period. This element is called the start bit and has a duration of T seconds. The transmitter then sends the character, l bit at a time, by placing each successive bit on the line for a duration of T seconds, until all bits have been transmitted. Then a single parity bit is calculated by the transmitter and sent after the data bits. Finally, the transmitter sends a stop bit at a mark level (i.e. the same level as the idle state) for one or two bit periods. Now the transmitter may send another character whenever it wishes.
At the receiving end of an asynchronous serial data link, the receiver continually monitors the line looking for a start bit. Once the start bit has been detected, the receiver waits until the end of the start bit and then samples the next N bits at their centers, using a clock generated locally by the receiver. As each incoming bit is sampled, it is used to construct a new character. When the received character has been assembled, its parity is calculated and compared with the received parity bit following the character. If they are not equal, a parity error flag is set to indicate a transmission error.
(1).When the transmitter wishes to send data, it first ().
A.places the line in a space level
B.puts the line in a mark level
C.sends a stop bit
D.places a bit at logical l level
(2).Then a single parity bit is calculated by the transmitter and ().
A.compared with the received parity bit
B.sent with the data bits
C.sent after the data bits
D.sent before the data bits
(3).At the receiving end of an asynchronous serial data link, the receiver continually monitors the line().
A.waiting for the end of the start bit
B.looking for a start bit
C.generating a clock
D.constructing a new character
(4).When the transmitter wishes to send data , it first sends().
A.a character at the same time
B.a character to the line
C.the start bit
D.a mark level to the line
(5).The transmitter then send the character, for a duration of T seconds().
A.each bit
B.all bits
C.successive bits
D.a start bit and a character
第4题
B.Label: 20 bits, with value of 13.
C.MEL: 3 bits, with value in range of 0_7, indicating MEG layer.
D.S: 1 bit, with value of 1, indicating packets processed by OAM module. TTL: 8 bits, indicating packet hop-count.
第5题
A.degree
B.calorie
C.gallon
D.liter
第6题
A.db
B.dbm
C.dbd
D.dbi
第8题
A.regrettably
B.forcibly
C.graciously
D.gravely
第9题
Directions: Fill in the blanks with the words and expressions froma list of choices given in a word bank following the passage. Each choiceshould be used only once. Maria is a failure as a n 1 . The Reverend Mother sends her off in answer t 2 a letter from a retired naval captain for a g 3 for his seven children. There is aloofness in Captain Von Trapp; however, it is just a disguise for the sadness caused by his wife’s death. Maria teaches the children to sing and brings vitality b 4 to the large house. The Captain loves singing and thanks Maria for what she has done for his family. He calls o 5 his engagement with the beautiful Baroness for he realizes that he has f 6 in love with Maria, and so has Maria. They get married and go on their h 7 . When they come back, the Nazis attempt to draft Captain Von Trapp i 8 the Naval Forces of The Third Reich. After their sensational p 9 at the music festival and with some help from the abbey, the Von Trapps escape o 10 the Alps into Switzerland.
第10题
1、A、read
B、reading
C、to read
D、having read
2、A、patterns
B、fashions
C、forms
D、models
3、A、estimated
B、predicted
C、designed
D、counted
4、A、Therefore
B、Hence
C、Moreover
D、Even so
5、A、deserving
B、demonstrating
C、defending
D、defining
6、A、involve
B、evolve
C、resolve
D、revolve
7、A、methods
B、ways
C、habits
D、techniques
8、A、Traditionally
B、Constantly
C、Similarly
D、Usually
9、A、measures
B、means
C、modes
D、manners
10、A、When
B、Now that
C、While
D、If
第11题