Methods of transport is one of the terms of shipment.（)

The network layer provides services to the transport layer．It can be based on either (1)．In both cases，its main job is (2) packets from the source to the destination．

In network layer，subnets can easily become congested，increasing the delay and (3).

for packets．Network designers attempt to avoid congestion by proper design．Techniques include (4) policy，caching，flowcontrol，and more．

The next step beyond just dealing with congestion is to actually try to achieve a promised quality of service．The methods that can be used for this include buffering at the client，traffic shaping，resource (5)，and admission control．Approaches that have been designed for good quality of service include integrated services(including RSVP) ，differentiated services， and MPLS．

(1)

A．virtual circuits or datagrams

B．TCP or UDP

C．TCP or IP

D．IP or ARP

Secondly, there is a problem of wastes. All nuclear power stations produce wastes which【9】will remain radioactive for thousands of years. It is【10】to de-active these wastes, and so they must be stored【11】one of the ingenious but cumbersome ways that scientists have invented. For example, they must be buried under the ground【12】sunk in the sea. However, these【13】do not solve the problem completely, they merely store it, since an earth-quake could【14】open the containers like nuts.

Thirdly, there is the problem of accidental exposure【15】to a leak or an explosion at the power station.【16】with the other two hazards, this is not very likely and does not provide a serious【17】to the nuclear program,【18】it can happen, as the inhabitants of Harrisburg will tell you.

Separately and during short periods, these three types of risk are no great cause for concern. 【19】though, and especially【20】much longer periods, the probability of a disaster is extremely high.

(1)

A．related

B．connected

C．associated

D．affiliated

When faced with the decision of selecting a mode of transportation, the exporter has five basic types available from which to choose, depending, of course, upon the geographicalproximity[1] of the countries of export and import: ocean, air, rail, truck, and inland water. A sixth alternative is pipeline which transports very specialized products. The choice between available methods of transportation is usually determined by a combination of cost , time , and security.

Ocean transportation is by far the most dominant mode of international transportation , and air transport is the most " glamorous" and fastest growing. The significance of the other basic types of international transportation varies depending upon the countries involved. For example,rail and truck shipments do not constitute a significant portion of the export transactions of the United States, except perhaps for those that involve buyers in Canada. In contrast,these transport modes carry large amounts of export goods among the countries of Europe. Similarly,inland waterways are not important carriers of goods between countries except in Europe where waterways such as the Rhine and Danube rivers carry large amounts of goods among the countries through which they flow. Often the use of these relatively less important modes of transport depends upon the nature of specific products in unique geographic situations. The use of trucks to haul fresh produce from northem Mexico to the United States illustrates this practice.

Ocean transportation is widely used because it is a relatively low-cost way to transport goods, and it can easily handle large shipments. In addition, certain geographic conditions may make it impossible to use overland transportation to some foreign markets andinfeasible[2] to use it to others.

Many diverse types of products are being transported to foreign markets by air in large volume-computers, office machines, electrical and electronic equipment, automobile parts, television sets,pharmceuticals[3], certain metal manufactures, and wearing apparel to name but a few. Thus , even with existing technology, it is evident that air cargo movements are no longer confined to fast shipments of emergency supplies, goods of high value , (for example ,jewel) and perishable products (for example , fresh flowers) , although it is widely used for such products. Not only is time in transit reduced from a minimum of 10 days to a few hours, but also less handling and simpler packing requirements are involved.

Time in transit is but one of the so-called hidden costs that may be relevant. For example,concerning time in transit and the ability to put a f'acility to use sooner (thus avoiding lost sales) ,a West German company bought 230hosiery-knitting machines[4] from a US manufacturer. The machines were shipped by air at a cost of USD 224 per unit which was considerably greater than the ocean rate of USD37. 80 per unit. Delivery time was shortened by 10 days giving the Cerman manuf'acturer the opportunity to produce 207 000 pairs of hosiery, which apparently offset the transportation cost.

Small shipments may be sent by intemational parcel post, air parcel post, or air couner service rather than pay the higher minimum bill of lading charges for ocean freight or air shipment. While larger shipments are charged on the basis of weight or measurement,very small shipments are charged a set flat fee because of the costs involved in documentation and handling.

The method of transportation is usually selected by the importer. The route selected for the export shipment may be determined by either the exporter or the importer. In practice , the importer should indicate the route he or she thinks is most desirable. The final selection of the exact route,however,should generally be left to thediscretion[5] of the exporter, since the exporter is more fully acquainted with conditions surrounding the shipment in the country from which it is sent, and particularly the immediate conditions at time of shipment.

[1]接近

[2]不可行的

[3]医药的

[4]针织品编织机

[5]判断力

Questions for reading :

Most people learn best using a variety of _________, but traditional classes are an ideal(理想的)start for many people. They _______ an environment where you can practice under the ________ of someone who’s good at the language. We all lead ________ lives and learning a language takes _______. You will have more success if you study regularly, so try to develop a ________. It doesn’t matter if you haven’t got long. Becoming fluent in a language will take years, but learning to get by takes ________.

Many people start learning a language and soon give up. “I’m too _______,” they say. Yes, children do learn languages more _______ than adults, but research has shown that you can learn a language at any ________. And learning is good for the health of your brain, too. I’ve also heard people ________ about the mistakes they make when ________. Well, relax and laugh about your mistakes ________ you’re much less likely to make them again.

Learning a new language is never ________. But with some work and devotion, you’ll make progress. And you’ll be _________ by the positive reaction of some people when you say just a few words in ________ own language. Good luck!

1.A. technical B. political C. practical D. physical

2.A. After B. So C. Though D. Or

3.A. literature B. transport C. agriculture D. medicine

4.A. view B. knowledge C. form. D. database

5.A. paintings B. regulations C. methods D. computers

6.A. protect B. change C. respect D. provide

7.A. control B. command C. guidance D. pressure

8.A. busy B. happy C. simple D. normal

9.A. courage B. time C. energy D. place

10.A. theory B. business C. routine D. project

11.A. some risks B. a lot less C. some notes D. a lot more

12.A. old B. nervous C. weak D. tired

13.A. closely B. quickly C. privately D. quietly

14.A. age B. speed C. distance D. school

15.A. worry B. hesitate C. think D. quarrel

16.A. singing B. working C. bargaining D. learning

17.A. if B. and C. but D. before

18.A. tiresome B. hard C. interesting D. easy

19.A. blamed B. amazed C. interrupted D. informed

20.A. their B. his C. our D. your

主动转运(active transport)