Recently some American scientists have given a useful piece of advice to people in industrialized nations．They say people should eat more of the same kind of food eaten by humans living more than 10,000 years ago． 1
The scientists say that the human life has changed greatly．Our bodies have not been able to deal with these changes in lifestyle and this had led to new kinds of sicknesses．2 So they are called "diseases of civilization"．Many cancers and diseases of the blood system are examples of such diseases.
Scientists noted that people in both the Old Stone Age and the New Stone Age enjoyed very little alcohol or tobacco, probably none． 3 However, a change in food is one of the main differences between life in ancient times and that of today.
Stone Age people hunted wild animals for their meat, which had much less fat than domestic ones．They ate a lot of fresh wild vegetables and fruits．They did not have milk or any other dairy products, and they made very little use of grains． 4 We eat six times more salt than our ancestors．We eat more sugar．We eat twice as much fat but only one third as much protein and much less vitamin C.
5 But scientists say that we would be much healthier if we eat much the same way the ancient people did, cutting the amount of fatty, salty and sweet food.
A．Stone Age people lived a simple life.
B．But today, we enjoy eating a lot of these.
C．In that case, they would live much healthier.
D．Ancient people also got lots of physical exercise.
E．These new sicknesses were not known in ancient times.
F．People today probably don't want to live like our ancestors.
G．Modern people used to suffer from "diseases of civilization".
We often think insects to be harmless. This is partly true. Many an insect are harmful. Flies carry diseases. Others insects carry diseases, too. Farmers are at war with insects most the time. Hunger insects kill crops in the fields Farmers spray the field as to get rid of these insects. Does this means that all insects are harmful? No. Many are of great helpful to man. Bees make honey. With bees and other insects, many trees would have not fruit. Silkworms make silk. Some insects eat other insects