But there are some parts of the world where even now people cannot write

The only way that they can preserve their history is to recount it as sagas-legends handed down from one generation of storytellers to another

These legends are useful beacause they can tell us something about migrations of people who lived long ago,,but none could write down what they did.Anthropologist wondered where the remote ancestors of the Polynesian peoples now living in the Pacific Islands came from.

The sagas of these people explain that some of them came from Indonesia about 2000 years ago.But the first people who are like ourselves lived so long ago that even their sagas,if they had any ,are forgotten.

So archaeologists have neither sagas nor legends to help them to find out where the first "modern men"came from

So archaeologists have neither sagas nor legends to help them to find out where the first"modern men"came from

Fortunately ,however,ancient men made tools of stone,especially flint,beacause this is easier to shaped than other kinds.They may also have used wood or skin,but they have rotted away.Stone does not decay,and so the tools of long ago have remained when the bones of the men who made them have disapeared without trace

第二弹

Why,you may wonder,should spiders be our friends?Beacause they destroy so many insets ,and insects include some of the greatest enemies of the human race.Insects would make it impossible for us to live in the world;they would devour all our crops and kill our flocks and herds ,if it were not for the protection we got from the insects-eating animals

We owe a lot to the birds and beasts who eat insects but all of them put together kill only a fraction of the number desroy by spiders.Moreover,unlike some of the other insect eaters,spiders never do the least harm to us and our belongings

How many spiders are engaged in this work on our behalf?