Increasingly ,over the past ten years ,people—especially young people—have become aware of the need to change their eating habits ,because much of the food they eat ,particularly processed foods ,is not good for the health .As a result ,there has been a growing interest in natural foods :foods which do not contain chemical fertilizers ,widely used in farming today .
Natural foods ,for example ,are vegetables ,fruit and grain which have been grown in soil that is rich in organic(有机的)matter . In simple terms ,this means that the soil has been nourished by unused vegetable matter ,which provides it with essential vitamins and minerals. This in itself is a natural process compared with the use of chemicals and fertilizers , the main purpose of which is to increase the amount—but not the quality—of food grown in commercial farming areas .
Natural foods also include animals which have been allowed to feed and move freely in healthy grassland for cattle .Compare this with what happens in the mass production of poultry (家禽):there are battery farms ,for example ,where thousands of chickens live crowded together in one building and are fed on food which is little better than rubbish .Chickens kept in this way are not only tasteless as food; they also produce eggs which lack important vitamins .
There are other things of healthy eating which are now receiving increasing attention from experts on diet .Take ,for example ,the question of sugar .This is actually a non-essential food! Although another natural food ,such as honey ,can be used to sweeten food if this is necessary ,we can in fact do without it .It is not that sugar is harmful in itself .But it does seem to be addictive : the quantity we use has grown steadily over the last two centuries and in Britain today each person consumes an average of 200 pounds a year !Yet all it does is provide us with energy ,in the form of calories .There are no vitamins in it ,no minerals ,and no fibre .
It’s very important that nowadays fibre is considered to be an important part of a healthy diet .In white bread ,for example ,the fibre has been removed .But it is present in unrefined flour and of course in vegetables .It is interesting to note that in countries where the national diet contains large quantities of unrefined flour and vegetables ,certain diseases are comparatively not often seen .For this reason ,the importance is placed on the eating of wholemeal(没有去麸的面粉)bread and more vegetables by modern experts on “healthy eating”.
People have become more interested in natural foods because            .

A．they want to keep fit

B．they want to taste all kinds of foods

C．natural foods are more delicious than processed foods

D．they want to return to nature

Chickens raised in poultry farms are all of the following EXCEPT that           .

A．they are fed on food which is little better than garbage

B．they live in very crowed condition

C．the eggs they produce lack vitamins

D．they are allowed to move about and eat freely

According to the passage,_________.

A．people need sugar to give them energy

B．sugar is bad for the health

C．the use of sugar is habit forming

D．sugar only sweetens food, but provides us with nothing useful