相关试题
【判断题】
朱自清的《给亡妇》具有明显的絮语散文的特点。
【判断题】
《清忠谱》和《桃花扇》集明清传奇之大成。
【判断题】
《定风波》(莫听穿林打叶声)体现了苏轼旷达的词风。
【单选题】
With increased taxation and rising prices, I am going to have to __________ on quite a lot of things – clothes, records and so on.___
A. cut off
B. cut in
C. cut out
D. cut down
【单选题】
Have a cup of tea, _______?___
A. shall we
B. will you
C. won't you
D. do you
【单选题】
There is very ___ hope that she will pass the exam.___
A. few
B. small
C. much
D. little
【单选题】
I am not sure whether we can give the right advice _____emergency.___
A. on account of
B. in case of
C. at the risk of
D. in spite of
【单选题】
In their letter to the students’ representative assembly, the freshmen insisted on __________ in the Student Union.___
A. represented
B. being represented
C. having represented
D. have been represented
【单选题】
Nobody noticed the thief slip into the house because the lights happened to _____.___
A. be put up
B. give in
C. be turned on
D. go out
【单选题】
----- John, may I ask you a favour? ----- _________
A. I’m sorry, but why?
B. Sure,what is it?
C. Yes,you could.
D. I’d love to,and I’m busy.
【单选题】
The two thieves fled the town separately, _______ a bag.___
A. each carrying
B. whose that watch is
C. whose watch is that
D. whose watch is
【单选题】
Her heart _____ faster when she entered the exam hall.___
A. jumped
B. sank
C. beat
D. hit
【单选题】
The taxi driver was put in_____prison because his car had knocked down a child.His wife went to_____ prison to see him twice a month.___
A. /; /
B. the; the
C. /; the
D. the; /
【单选题】
----- Where’s John, do you know? ----- Oh, _____to hospital.___
A. he’s taken
B. he’ll be taken
C. he’s been taken
D. he’ll take
【单选题】
It was the wealth of the_____pioneer landowner John Harvard that made Harvard University possible.___
A. precious
B. curious
C. anxious
D. prosperous
【单选题】
----- "Where is your college located, John?" ----- "It is ________."___
A. on the Fifth Avenue
B. on Fifth Avenue
C. in Fifth Avenue
D. at Fifth Avenue
【单选题】
__________ is she in London than she rings up her old friend Mary.___
A. Scarcely
B. Rarely
C. No sooner
D. Hardly
【单选题】
A fireman discovered the __________ of the fire.___
A. truth
B. reason
C. cause
D. fact
【单选题】
he weather __________ us from climbing the mountain.___
A. discharged
B. disguised
C. disturbed
D. discouraged
【单选题】
I didn't expect to receive a postcard from you!It's really _____my wildest imagination.___
A. behind
B. beyond
C. except
D. through
【单选题】
John Smith is _____ honest young man.___
【单选题】
She __________ in wearing that old – fashioned hat.___
A. insists
B. persists
C. assists
D. consists
【单选题】
Some of the meat came from Canada. How about________?___
A. another
B. the other
C. others
D. the rest
【单选题】
I have brought you ___ flowers for your birthday. ___
A. few
B. a few
C. little
D. a little
【单选题】
I have also experienced many adventures, but nothing that I have seen ___what you have described. ___
A. compares
B. relates
C. resembles
D. assembles
【单选题】
That young man has made so much noise that he ___ not have been allowed attend the concert. ___
A. could
B. must
C. would
D. should
【单选题】
“What is Mary doing at home?” “She is playing ____.”___
A. a piano
B. her piano
C. piano
D. the piano
【单选题】
I’m busy now ,ask him to see me ____ time.___
A. the other
B. some other
C. other
D. another
【单选题】
The child took a spoonful and tasted it carefully __________ it was hot.___
A. in case
B. provided
C. if
D. unless
【单选题】
The French pianist who had been praised very highly __________ to be a great disappointment. ___
A. turned off
B. turned up
C. turned out
D. turned down
【单选题】
“Shall I turn on the television?” – “No, I’d rather not __________ television tonight.”___
A. have watched
B. to watch
C. watch
D. for watching
【单选题】
They said that they had made up their minds to ____the task in spite of the extremely difficult conditions.___
A. carry on
B. carry off
C. carry away
D. carry forward
【单选题】
The two girls are getting on very well and share with each other. ___
A. little
B. much
C. some
D. none
【单选题】
The teacher said that the classroom was empty __________ a few chairs.___
A. but for
B. except for
C. apart from
D. besides
【单选题】
______you choose, make sure that it is a good one. ___
A. What
B. Wherever
C. Whichever
D. Which
【单选题】
Vingo was released from prison_____the successful efforts of his friends to prove his innocence. ___
A. according to
B. as a result of
C. for reasons of
D. with the help of
【单选题】
Entering the room, I found my father __ at the desk and ___ something .___
A. seat... write
B. seated ... wrote
C. seated ... writing
D. seating ... writing
【单选题】
Cake __________ of flour, sugar, egg and some other ingredients. ___
A. contained
B. consists
C. includes
D. composed
推荐试题
【判断题】
G.652光纤为常规单模光纤,其特点在波长1.31μm处色散为零,系统的传输距离一般只受损耗的限制。
【判断题】
单模光纤与多模光纤相比,单模光纤传输距离较远。
【判断题】
光纤的衰减指的是光在光纤中传输时的能量损耗。
【判断题】
光纤接头有很多型号,其中SC/PC表示方型斜面光纤接头。
【判断题】
光纤由纤芯和包层组成,为保证光的传导,纤芯的折射率应小于包层的折射率。
【判断题】
光纤有单模式和多模式两种,光纤的接口标准有ST、FC、SC、LC和MTRJ等。
【判断题】
由于光纤上传输的光信号为不可见光,所以可以用肉眼直接观看光口。
【判断题】
光时分复用(OTDM)技术的复接可分为两种,即以比特为单位进行逐比特顺序连接和以比特组为单位的逐组交错复接。
【判断题】
纤芯(core),折射率较高,用来传送光,包层(coating),折射率较低,与纤芯一起形成全反射条件;保护套(jacket),强度大,能承受较大冲击,保护光纤。
【判断题】
STM也称为时分复用(TDM),不同设备和业务的比特流在传输过程中被分配固定的带宽。
【判断题】
光纤接头有很多型号,其中FC/PC表示圆型平面光纤接头。
【判断题】
光纤的光功率大于设备的灵敏度时,一般不会对设备造成影响
【判断题】
回波损耗又称为反射损耗,它是指在光纤连接处,后向反射光相对输入光的比率的分贝数。所以回波损耗愈小愈好,以减少反射光对光源和系统的影响。
【判断题】
光缆成端接续有冷接和热熔两种方式,为保证线路质量,原则上要求采用热熔方式。
【判断题】
FTTB接入方式,从局端至用户端全程使用光纤接入。
【判断题】
FTTB模式又分为FTTB+LAN和FTTB+xDSL两种方式。
【判断题】
PON网络由光线路终端(OLT)、光配线网(ODN)和光网络单元(ONU)三大部分组成。
【判断题】
PON为无源光网络,所以在PON系统中无有源器件。
【判断题】
PON中的ODN位于ONU和OLT之间,ODN全部由无源器件构成,它具有无源分配功能
【判断题】
在接入网中,如果全部由无源器件组成,不包括任何有源节点,则这种光接入网就是PON。
【判断题】
EPON分配给每个ONU的上行接入带宽由OLT控制决定。
【判断题】
EPON目前可以提供上下行对称的1.25Gbps的带宽
【判断题】
EPON使用TDM技术实现上下行数据在同一根光纤内传输,互不干扰。
【判断题】
EPON技术中下行采用的是广播的方式,每个ONU都会接收OLT发送的所有数据。
【判断题】
EPON系统中,OUN到OLT的距离最大可以是20KM。
【判断题】
EPON系统中采用双纤技术解决数据上下行传输。
【判断题】
EPON系统中下行采用1490nm/上行采用1310nm的波长进行双向传输。
【判断题】
EPON由于采用波分复用技术,ONU随时可以向OLT发送数据。
【判断题】
EPON下行为广播方式,所有的ONU都能收到相同的数据,但通过LOID来区分不同的ONU的数据,ONU过滤广播接收属于自己的数据。
【判断题】
GPON测距技术等保证上行数据不冲突。
【判断题】
GPON和EPON均采用8B/10B线路编码,下行效率较高。
【判断题】
GPON技术中,从OLT到ONU的下行方向中采用广播发送数据流的传输方式。
【判断题】
GPON是基于以太网的无源光接入技术,遵循IEEE 802.3ah系列标准。
【判断题】
GPON系统采用GEM封装方式,把任何业务(TDM和分组)都通过GFP装入125微秒的幀中,封装简单高效;能提供端到端业务管理的OAM&P强大功能。
【判断题】
ODN,即光纤分配网络,包含光分路器、光纤光缆及光缆分线盒、光缆交接箱等一系列无源器件。
【判断题】
ODN馈线光缆就是用户接入层光缆的主干光缆。