根据下面SHELL程序内容，回答问题。 #!/bin/bash i=1 while [ $i -le 50 ] # （1) do userdel -r stud${i} # （2) i=$（（$i+1 )) # （3) done echo "remove sucessful!" 上述程序为对用户操作的代码，试对其行后有#（n）形式的语句进行解释，并说明该程序完成的功能。

根据下面内容，回答下列各题。 The increase in the margin rate (保证金率)from 50% to 70% was not an attempt to stem any rampant (猛烈的)speculation on the part of the public-actually the market seemed technically quite strong, with public participation essentially dignified-but rather an attempt by the Federal Reserve Board to preserve the sound underpinnings that existed in the market. Naturally, such a move had a____36____chilling effect upon prices but if the FRB had been preoccupied with undue speculation, the increase might have been to the 80% or even 90% level. Such increases in the margin rate is a____37____of a strong stock market and since 1989, such increases have resulted in interim market highs over twelve months later. Obviously, there could be no____38____that this would once again be the case, but if history is any guideline-and if business and corporate earnings were to continue on the same course-continued optimism over the outlook for the stock market would seem more____39____than pessimism. The margin increase ____40____the good rise that stocks had enjoyed for the previous year-and the fact that a 50% rate was maintained as long as it was pointed up the fact that the rise was mainly conservative in that it was concentrated in the blue chips for the most part. In past Investment Letters we have____41____the thought that speciality stocks could outperform. the general market from this point. We continue to believe that this could be the case. For example, steel stocks tend to sell at a certain fixed price/earnings ratio. Below a certain ratio they are considered good value-above a certain ratio,____42____. If a company produces a unique product, it is far more difficult for market analysis to place a numerical ratio upon the companys earnings. We have also contended in the past Letters that the stock market reflects mass psychology as well as the business outlook. When investors-both the public and the institutions-are nervous and____43____they definitely hesitate to buy stocks: they seek low price/earnings multiples and high____44____. These same investors-when they are in an optimistic frame. of mind--become far less____45____ with yields and more willing to pay a premium( high p/e multiples)for accelerated growth. If the publics attitude towards the auto industry is any measure, then this period seems to have been one of optimism.

A.confirmation

B.guarantee

C.intelligible

D.invariably

E.momentarily

F.overpriced

G.pessimistic

H.preoccupied

prudent

representation

speculate

underscored

vicinity

voiced

yields 第36题答案为（ ）

根据短文回答 46～50 题。

The Roadrunner

The roadrunner(走雀)lives in the desert zone of the southwestern United States and northern Mexico.___________ (46)People gave it its name because they Usually see it running across a road,but of course,it spends more time among the plants of the desert than it does on roads.

The roadrunner is quite a large bird-about 45 centimeters long and 25 centimeters high.___________(47)It holds its head straight out in front and its tail sticks straight。Out in back.It takes long steps and can run 30 kilometers an hour.

It eats an amazing variety of food.Although it eats plants once in a while,it is mostly a meat eater.Most of its diet is insects,but it also catches birds,mice。and other smile animals.It is even brave enough to catch snakes and black widow spiders(蜘蛛) ___________ (48)When he finds one,he gives her presents-a snake to eat or a tiny branch of a tree to use in building a nest.Then they build their nest,the female lays eggs,and they raise their young.

___________ (49) one couple in Arizona feeds a pair of roadrunner that come once at a time every day and make a noise outside the window.If Someone doesn't give the bird a piece of hamburger immediately, the bird knocks on the window with its beak (喙).Roadrunners are not shy.

___________ (50)They will stand on a chair or table and watch television and they seem really interested in what is happening on the program.（ ）

A．Roadrunners can also become friendly with people.

B．People laugh when it runs because it looks so funny.

C．It is a bird,but it can only fly about as much as a chicken can.

D．In early spring.the bird doesn't eat anything.

E．Another couple feeds a pair of roadrunners that go right into the house.

F．In the spring,a male roadrunner begins looking for a female as a mate.

第 46 题 请选择（46）处的最佳答案

有以下程序

main()

{ int i,s=1;

for (i=1;i<50;i++)

if(!(i%5)&&!(i%3)) s+=i;

printf("%d\n",s);}

程序的输出结果是

A．409

B．277

C．1

D．91

下图(a)所示电路，U=200 V，P=1500W，f=50Hz，R₁=R₂=R₃=R，I₁=I₂=I₃=I。求I，R，L，C各为多少?

   

有程序： main( ) { int x，i; for(i＝1；i＜50；i+ +) { x＝i； if(+ +%2＝＝0) if(x%3＝＝0) if(x%7＝＝0) printf("%d"，i)； } } 输出结果是 ( )

A．28

B．27

C．42

D．41

根据下面内容，回答题：

Coffee is worth approximately $ 50-60bn per annum in terms of world sales. It is a truly international commodity， and today more than 50 countries in the world grow coffee beans. （0）________13 ICO consists of61 governments， 43 of which are exporters and 18 of which are importers. The organi- zation helps coffee producers and promotes coffee consumption worldwide. ICO esti- mates that world production next year will reach 97. 5 million bags， ll. 3 million bags higher than the current year. （8）________ As the largest producing country， Brazil is par- ticularly important in the coffee world. In1994 Brazil was responsible for 25% of world production， Colombia was next with13.4%， Indonesia had 7.5%， Mexico4. 7%， Guatemala 3.8% and Ethiopia and Vietnam were equal with 3.4%.

Coffee is a tough crop， and can be grown in areas where it is difficult or impossible to grow other crops. （ 9 ）________ However， disease is always a problem for coffee production， as we can see in some parts of South America at the moment. ICO is active in educating farmers about avoiding disease and dealing with problems when they occur. The distribution chain varies from country to country， explains Pablo Dubois. In most countries the smaller farmers sell their crop to a local trader， who then sells it on to ex- porters. There are， however， other distribu- tion systems. （ 10 ）________ Some countries， like Vietnam， have special government mar- keting organizations for coffee.

Coffee prices often vary greatly from one year to the next. In 1997， for example there was a large rise in the world price， which was immediately felt by the consumer. Rising prices always result in a drop in sales， which will have a bad effect on those developing countries which are highly dependent on foreign exchange from coffee exports. （ 11 ）________

In the opinion of Pablo Dubois， the biggest problem for his organization is to create greater consumer awareness of the different varieties of coffee and different ways of preparing it. （ 12 ） ________ICO is therefore concentrating its promotional activities on Russia and China. It is also encouraging environmentally friendly coffee production， and last year"s seminar on coffee and the environment created a lot of interest.

The future looks bright for the coffee industry. It is estimated that consumption over the next few years will continue to rise steadily. New markets like Eastern Europe and China are expected to develop fast.

A．As a result， the membership now represents 94% of all exporters and 60% of all importers.

B．In some of these countries， this can amount to as much as 50% of all export earnings.

C．In North America， most consumers already have above-average knowledge of the range available.

D．For example， frost and wind are particularly damaging to coffee crops. E Larger coffee growers， for example， frequently export directly.

F．The main reason for this is higher Brazilian output as production recovers from weather damage to crops.

G．It is cultivated in mountain regions which can only be reached by animal transport，and in other difficult areas where modern agricultural equipment cannot be used.

__________

查看材料

图(a)所示电路中，已知R₁=R₂=R₃，I₁=I₂=I₃，P=1500W，U=150V，f=50Hz。求元件R₁，R₂，R₃，L及C值。

  

图6-63所示为一正弦交流电路，已知U=200V，P=1500W，f=50Hz，R₁=R₂=R₃=R，I₁=I₂=I₃=I，问I，R，L，C各为多少?

  

下面程序的功能是计算1+2+3……+50的和。

main()

(int i，sum；

for(i=1；i＜=50；i++)

sum+ =i;

printf("%d"，sum)；

}

错误：______

改正：______

参考答案：错误