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? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Electricity

The modern age is an age of electricity, People are so used to electric lights, radio, televisions and telephones that it is hard to imagine what life would be like without them. When there is a power failure, people grope about in flickering candlelight,

cars hesitate in the streets because there are no traffic lights to guide them, and food spoils in silent refrigerators. Yet, people began to understand how electricity works only a little more than two centuries ago. Nature has apparently been

experimenting in this field for millions of years. Scientists are discovering more and more that the living world may hold

many interesting secrets of electricity that could benefit humanity.

All living cells send out tiny pulses of electricity. As the heart beats, it sends out pulses of record; they form an electrocardiogram, which a doctor can study to determine how well the heart is working. The brain, too, sends out brain waves of electricity, which can be recorded in an electron-cephalogram. The electric currents generated by most living cells are extremely small-often so small that sensitive instruments are needed to record them. But in some animals, certain muscle cells have become so specialized as electrical generators that they do not work as muscle cells at all. When large numbers of these cells are

linked together, the effects can be astonishing.

The electric eel is an amazing storage battery. It can send a jolt of as much as eight hundred volts of electricity through the

water in which it lives. An electric house current is only one hundred twenty volts )As many as four fifths of all the cells in the electric eel's body are specialized for generating electricity, and the strength of the shock it can deliver corresponds roughly

to the length of its body.

1

【單選】

What is the main idea of the passage?

A

Electric eels are potentially dangerous

B

Biology and electricity appear to be closely related

C

People would be at a loss without electricity

D

Scientists still have much to discover about electric

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考點：閱讀選擇

統(tǒng)觀全文可知,文章用了大量的篇幅介紹生物和電流的密切關(guān)系。

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? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Rare Fossil Record

? ? ?The preservation of embryos and juveniles is a rare occurrence in the fossil record. The tiny delicate skeletons are

usually scattered by scavengers(食腐動物)weathering before they can be fossilized Ichthyosaurs(魚龍) had a higher chance of being preserved than did terrestrial creatures be-cause, as marine animals, they tended to live in environments less

subject to erosion. Still, their fossilization required a suite of factors: a slow rate of decay of soft tissues, little scavenging by

other animals, a lack of swift currents and waves to jumble and carry away small bones, and fairly rapid burial. Given these

factors, some areas have become a treasury of well-preserved ichthyosaur fossils.

? ? The deposits at Holzmaden, Germany, present an interesting case for analysis. The ichthyosaur remains are found in

black, bituminous marine shales(頁巖)deposited about 190 million years ago. Over the years, thousands of specimens of

marine reptiles, fish and invertebrates have been recovered from these rocks. The quality of preservation is outstanding, but what is even more impressive is the number of ichthyosaur fossils containing preserved embryos.

? ? Ichthyosaurs with embryos have been reported from 6 different levels of the shale in a small area around Holzmaden,

suggesting that a specific site was used by large numbers of ichthyosaurs repeatedly over time. The embryos are quite

advanced in their physical development; their paddles, for example, are already well formed. One specimen is even

preserved in the birth canal. In addition, the shale contains the remains of many newborns that are between 20 and 30

inches long.

? ? ?Why are there so many pregnant females and young at Holzmaden when they are so rare else-where? The quality of

preservation is almost unmatched and quarry operations have been carried out carefully with an awareness of the value of

the fossils. But these factors do not account for the interesting question of how there came to be such a concentration of

pregnant ichthyosaurs in a particular place very close to their time of giving birth.

11

【單選】

All of the following are mentioned as factors that encourage fossilization except the?_____

A

speed of burying

B

conditions of the water

C

rate at which soft tissues decay

D

cause of death of the animal

Which of the following is true of the fossil deposits discussed in the passage?_____

A

They include examples of newly discovered species.

B

They contain large numbers of well-preserved specimens.

C

They are older than fossils found in other places.

D

They have been analyzed more carefully than other fossils.

The word"outstanding"in Paragraph 2 is closest in meaning to_____

A

extensive

B

surprising

C

vertical

D

excellent

Why does the author mention the specimen preserved in the birth canal?_____

A

To illustrate that the embryo fossils are quite advanced in their development

B

To explain why the fossils are well preserved

C

To indicate how the ichthyosaurs died

D

To prove that ichthyosaurs are marine animals

Which of the following best expresses the relationship between the first and second paragraphs_____

A

The first paragraph describes a place while the second paragraph describes a field of study

B

The first paragraph defines the terms that are used in the second paragraph.

C

The second paragraph describes a specific instance of the general topic discussed in the first paragraph.

D

The second paragraph presents information that contrasts with the information given in the first paragraph.

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