listen to the material carefully,although it is difficult and sometime you can't write down the correct answer.As long as you have tried,whatever you write down will be the harvest of yours.You should believe that only by accumulating little by little could you learn English welll.so come on.
Why ,you may wonder ,should spiders be our friends?Because they destroy so many insects,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 folcks and herds,if it were not for the protection we get from insects-eating animals.(1)_______________________.Moreover,unlike some of the other insect eaters,spiders never do the least harm to us or our belongings.
Spiders are not insects ,as many people think,nor even nearly related to them.(2)_______________________.
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,and he estimated that there were more than 2,250,000 in one acre;that is something like 6,000,000 spiders of different kinds on a football pitch.Spiders are busy for at least half the year in killing insects.(3)_______________________.It has been estimated that the weight of all the insects destroyed by spiders in Britain in one year would be greater than the total weight of all the hunman beings in the country.
1 we owe a lot to the birds and beasts eat insects. But all of them put together kill only a fraction of the number destoryed by spiders.
2 one can tell the difference almost at glance, for a spider always has eight legs and insect never more than six.
3 it is impossible to make more than the wildest guess at how many they kill, but they are hungry creatures not content with only three meals a day.
1. we owe a lot the birds and beast who eat insects, but all of them put into together kill a only fraction of number destroyed by spiders
2. one can tell the difference almost at a glance, for the spider always has eight legs and insect never more than six
3. it is impossible to make more than the wildest guess at how many thet kill, but they are hungry creature, not content with only three meals a dsy
发表于 2011-1-18 15:39
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listen to the material carefully,although it is difficult and sometime you can't write down the correct answer.As long as you have tried,whatever you write down will be the harvest of yours.You should believe that only by accumulating little by little could you learn English welll.so come on.
发表于 2012-11-29 11:49
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