According to Para. 2, information superhighway is, in fact, ______.

Coffee is one of the most popular drinks throughout the world today. In fact, according to some estimates, over 30% of all adults in the world drink coffee at least once a day on the average. Coffee contains a kind of drug called caffeine. (66) Caffeine is a chemical substance that stimulates the nerves of the body. Drinking coffee tends to make people a little bit more awake, —at least for a short time—because of this stimulating effect on the nervous system. A cup of coffee has, on the average, about 3% caffeine in it.

One story of the discovery of the coffee plant relates to this effect of caffeine. According to the story, coffee was discovered in East Africa. The story says that coffee was first found by a goat farmer named Kaldi. This was about the year 850.

Kaldi was leading his animals through the mountains and the goats were stopping repeatedly to eat the plants near the path. Suddenly, some of the goats started jumping up and down in a very strange way.

Kaldi figured out that the goats were acting this way because of the plants they were eating. Kaldi himself tried eating some of the green beans that the goats had been eating. He, too, felt the stimulating effect of the beans.

Kaldi wanted to prove what had happened, so he picked some of the beans and took them back to his home village, where he told his story. The green bean got the name "Kaffa" and later "coffee" because the beans were discovered in a place called Kaffa in Africa.

Then for years, people used to eat a few of the green Kaffa beans when they were in the mountains and needed extra energy or stimulation. It was later found that the coffee beans could be picked and then dried until they turned brown, and then they could be stored. If the beans were dried and stored, they could be used at any time.

Caffeine is a kind of drug that can______.

A．strengthen one's heart

B．make one's bones strong

C．make one more active or alert

D．ease the pain on the body

A、tasty

B、foreign

C、toxic

D、native

In the early 1950s the researchers who produced the first clad glass optical fibers were not thinking of using them for communications.【46】H______, fiber optics was already a well-established commercial technology when the famous paper by Kao and Hockham,【47】______ (claim) the use of low-loss optical fibers for communication, appeared in 1966. The first low-loss silica fiber was described in【48】______which appeared in October of 1970. The date of this publication is sometimes【49】______(cite) as the beginning of the era of fiber communication. Although this development did receive【50】______ (consider) attention in the research community at the time, it was far from inevitable that a major industry would evolve.

The technological barriers appeared formidable because there were serious doubts as to【51】 wh______these fiber components could ever be produced economically enough, but the market potential was very significant.【52】______(consequence) , research and development activity expanded rapidly, and a number of important issues were【53】re______during the early 1970s. During the middle and late 1970s, the rate of progress towards marketable products accelerated as the emphasis【54】______(shift) from research to engineering. Fibers with losses【55】app______the Rayleigh limit of 2 dB/km at a wavelength of 0. 8 μm were produced.

By 1980 improvement in component performance, cost, and reliability led to major commitments on the part of telephone companies.

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