【正文】 s sanitation facilities, too. If fully occupied, the two World Trade Center towers in New York City would alone generate million gallons of raw sewage each yearas much as a city the size of Stanford, Connecticut , which has a population of more than 109, 000. 14 A Rare Fossil Record The preservation of embryos and juveniles is a rate occurrence in the fossil record. The tiny, delicate skeletons are usually scattered by scavengers or destroyed by weathering before they can be fossilized. Ichthyosaurs had a higher chance of being preserved than did terrestrial creatures because, 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 bee a treasury of wellpreserved ichthyosaur fossils. The deposits at Holzmaden, Germany, present an interesting case for analysis. The ichthyosaur remains are found in black, bituminous marine shales 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。 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 electroencephalogram. 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 bee so specialized as electrical generators that they do not work as muscle cells at all. When large numbers of these cell are linked together, the effects can be astonishing. The electric eel is an amazing storage battery. It can seed a jolt of as much as eight hundred volts of electricity through the water in which it live. ( An electric house current is only one hundred twenty volts.) As many as fourfifths 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 length of its body. 背 誦 篇 章 3 05 The Beginning of Drama There are many theories about the beginning of drama in ancient Greece. The on most widely accepted today is based on the assumption that drama evolved from ritual. The argument for this view goes as follows. In the beginning, human beings viewed the natural forces of the worldeven the seasonal changesas unpredictable, and they sought through various means to control these unknown and feared powers. Those measures which appeared to bring the desired results were then retained and repeated until they hardened into fixed rituals. Eventually stories arose which explained or veiled the mysteries of the rites. As time passed some rituals were abandoned, but the stories, later called myths, persisted and provided material for art and drama. Those who believe that drama evolved out of ritual also argue that those rites contained the seed of theater because music, dance, masks, and costumes were almost always used, Furthermore, a suitable site had to be provided for performances and when the entire munity did not participate, a clear division was usually made between the acting area and the auditorium. In addition, there were performers, and, since considerable importance was attached to avoiding mistakes in the enactment of rites, religious leaders usually assumed that task. Wearing masks and costumes, they often impersonated other people, animals, or supernatural beings, and mimed the desired effectsuccess in hunt or battle, the ing rain, the revival of the Sunas an actor might. Eventually such dramatic representations were separated from religious activities. Another theory traces the theater39。 not only is the cash prize itself considerable, but it also dramatically increases sales of an author39。 third, association among the subgroups and the majority population. Finally, it is worth noting that the terms standard colloquial and slang exist only as abstract labels for scholars who study language. Only a tiny number of the speakers of any language will be aware that they are using colloquial or slang expressions. Most speakers of English will, during appropriate situations, select and use all three types of expressions. 背 誦 篇 章 6 11 Archaeology Archaeology is a source of history, not just a bumble auxiliary discipline. Archaeological data are historical documents in their own right, not mere illustrations to written texts, Just as much as any other historian, an archaeologist studies and tries to reconstitute the process that has created the human world in which we live and us ourselves in so far as we are each creatures of our age and social environment. Archaeological data are all changes in the material world resulting from human action or, more succinctly, the fossilized results of human behavior. The sum total of these constitutes what may be called the archaeological record. This record exhibits certain peculiarities and deficiencies the consequences of which produce a rather superficial contrast between archaeological history and the more familiar kind based upon written records. Not all human behavior fossilizes.