新概念英语4-课文资料讲解

NEW CONCEPT ENGLISH(IV)

(new version)

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Lesson1Finding Fossil man

We can read of things that happened5,000years ago in the Near East,where people first learned to write.But there are some parts of the world where even now people cannot write.The only w ay that they can preserve their history is torecount it as sagas--legends handed down from one generation of story-tellersto another.These legends are useful because they can tell us somethin g aboutmigrations of people who lived long ago,but none could write down what they did. Anthropologists wondered where the remote ancestors of the Polynesianpeoples now living in th e Pacific Islands came from.The sagas of these peopleexplain that some of them came from Indo nesia about2,000years ago.But the first people who were like ourselves lived so long ago that ev en theirsagas,if they had any,are forgotten.So archaeologists have neither history nor legends to help them to find out where the first'modern men'came from.Fortunately,however,ancient me n made tools of stone,especially flint,becausethis is easier to shape than other kinds.They may also have used woodand skins,but these have rotted away.Stone does not decay,and so the tool s oflong ago have remained when even the bones of the men who made them have disappeared without trace.

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Lesson2Spare that spider

Why,you may wonder,should spiders be our friends?Because they destroy somany insects,and insects include some of the greatest enemies of the humanrace.Insects would make it impossible for us to live in the world;they woulddevour all our crops and kill our flocks and herds,if it were not for the protectionwe get from insect-eating animals.We owe a lot to the birds and beasts wh o eat insects but all of them put together kill only a fraction of the number destroyed by spiders. Moreover,unlike some of the other insect eaters,spiders never dothe least harm to us or our bel ongings.Spiders are not insects,as many people think,nor even nearly related to them.One can t ell the difference almost at a glance for a spider always has eight legsand an insect never more th an six.How many spiders are engaged in this work on our behalf?One authority on spiders made a census of the spiders in a grass field in the south of England,andhe estimated that there were more than2,250,000in one acre,that is something like6,000,000spiders of different kinds on a f ootball pitch.Spiders are busy for at least half the year in killing insects.It is impossible to make more than the wildest guess at how many they kill,but they are hungry creatures,not content wi th only three meals a day.It has been estimated that the weight of all the insects destroyed by spi ders in Britain in one year would be greater than the total weight of all the human beings in the c ountry.T.H.GILLESPIE Spare that Spider from The Listene

Lesson3Matterhorn man

Modern alpinists try to climb mountains by a route which will give them goodsport,and the more