PPP（Point—t0—PointProtocol，点到点的协议）是一种在同步或异步线路上对数据包进行封装的数据链路协议，早期的家庭拨号上网主要采用SLIP协议，而现在更多的是用PPP协议。

A.PPP

B.帧中继FrameRelay

C.X.25

D.LAPB

A. TK1(config-if)# encapsulation hdlc ansi

B. TK1(config-if)# encapsulation ppp

C. TK1(config-if)# encapsulation LAPD

D. TK1(config-if)# encapsulation frame-relay ietf

E. TK1(config)#encapsulation ppp

A.the upper α/2 percentage point of the t distribution with n1+n2-1 degrees of freedom

B.the upper α/2 percentage point of the t distribution with n1+n2-2 degrees of freedom

C.the lower α/2 percentage point of the t distribution with n1+n2-1 degrees of freedom

D.the lower α/2 percentage point of the t distribution with n1+n2-2 degrees of freedom

ey do not actually hear every word.They also fail to understand that they integrate their knowledge about language with their experience and knowledge of such things as topic and culture, and do not need to hear to hear every word. This means that learners Often have unrealistic expectations and try to understand each word Of a listening text. As some experts point 0ut，“such total comprehension…is a misconception 0f how normal comprehension works in the native language.” Learners’anxiety may get worse when a classroom procedure does not provide adequate context for the text Or prepare the topic by activating their prior knowledge;in Other words，a procedure which asks students to“Listen to the text and then answer the questions.” This tests listening ability rather than aiming to teach it.Adults returning to English language learning whose earlier experiences have been of this nature may have developed negatlve perceptions 0f their ability as 1isteners and a maior task for the teacher will be to build confidence. This means recognizing anxiety and a major tasking care to provide positive classroom experiences.For example，the teacher needs to make sure that the pace and length of a 1istening activity is not too taxing as the concentration required in trying to cornprehend unfamliliar sounds can be tiring.

21.When they comprehend their native language by 1istening，many language learners tend to think that they_____

A.need to hear every word

B.have linguistic knowledge

C.know the culture very well

D.have some existing experience

22.According to the passage,foreign language learning depends very much upon_____.

A.native lauguage competence

B.ability to concentrate

C.experience and knowledge

D.personal preference

23.This passage is mainly about _______.

A.writing

B.speaking

C.reading

D.1istening

24.The language teacher should _______.

A.develop negative perceptions Of students’ability

B.activate the prior knowledge students have

C.refer t0 the past experience 0f adult 1earners

D.help students understand their native 1anguage first

25.The word “taxing” in the last sentence probably means

A.costly

B.demanding

C.anxious

D.interesting

Section B

Directions:There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked [A], [B], [C]and [D].You should decide on the best choice and mark the corresponding letter onAnswer Sheet 2 with a sin-gle line through the centre.

Passage OneQuestions 57 t0 61 are based on the following passage.

Children leam almost nothing from television, and the more they watch the less they remember. They regard television purely as entertainment, resent programs that demand on them and are surprised that anybody should take the medium seriously. Far from being over-excited by programs, they are mildly bored with the whole thing.These are the main conclusions from a new study of children and television. The author Cardiac Cullingford confirms that the modem child is a dedicated viewer. The study suggests that there is little point in the later hours. More than a third of the children regularly watch their favorite programs afier 9 p.m. All ll-year-olds have watched programs afier midnight.

Apart from the obvious waste of time involved, it seems that all this viewing has little effect. Children don't pay close attention, says Cullingford, and they can recall few details. They can remember exactly which programs they have seen but they can rarely explain the elements of a particular plot. Recall was in "reverse proportion to the amount they had watched". It is precisely because television, unlike a teacher, demands so little attention and response that children like it, argues Cullingford. Programs seeking to put over senous messages are strongly disliked. So are people who frequently talk on screen. What children like most, and remember best, are the advertisements. They see them as short programs in their own right and particularly enjoy humorous presentation. But again, they react strongly against high-pressure advertisements that attempt openly to influence them.

On the other hand. they are not emotionally involved in the programs. If they admire the stars, it is because the actors lead glamorous Iives and eam a lot of money, not because of their fictional skills with fast cars and shooting villains (忍棍 ). They are perfectly clear about the functions of advefiisements; by the age of 12, only one in ten children believe what even favorite ads say about the product. And says Cullingford, educational television is probably least successful of all in imparting attitudes or information.

57. The study of children and television implies that _.

A. delaying TV programs to the later hours seems to be useless

B. watching TV until midnight is especially harmful to children

C. children should shorten their time on TV programs

D. children are supposed to Ieam a Iot from television programs

A.T0、T1

B.T0、T2

C.T1、T0

D.T2、T0

A.T= TL + T0

B.TL= T + T0

C.T+ TL+ T0 = 0

D.T0= T + TL

A.T0/2

B.2 T0

C.1/2lg T0

D.2lg T0

定时器T0的中断入口地址是( )。

A.dt,X,Y

B.t0，X,Y

C.t0，dt，Y

D.t0，dt，dY