Put the jumbled sentences in the logical order.

 

1. The beetles immediately disappear beneath the pats and tunneling.

2. Chemical fertilizer and dung would be washed by rain into streams and rivers if it were not for the dung beetle.

3. Dung beetles were introduced into farming in the early 1960s to control dung-breeding flies.

4. There are some evident benefits of using dung beetles.

5. If the beetles didn’t dispose of the dung cow pats would litter pastures and grass inedible to cattle.

 

UNIT XXVII

Key words and expressions: to lack, to cause, depressed, exposure, fluorescent, to be exposed to, a mood, melatonin.

 

Pre-reading tasks

Look at the title of the text and guess what the text is about.

 

Highs and Lows

Hormone levels - and hence our moods - may be affected by the weather. Gloomy weather can depression, but sunshine appears to raise the spirits. In Britain, for example, the dull weather of winter drastically cuts down the amount of sunlight that expended which strongly affects some people. They become so depressed and lacking m energy that is work and social life are affected. This condition has been given the name SAD (Seasonal Affective Disorder). Sufferers can fight back by making the most of any sunlight in winter and by spending a few hours each day under special, full-spectrum lamps. These provide more ultraviolet and blue-green light than ordinary fluorescent and tungsten lights. Some Russian scientists claim that children learn better after being exposed to ultraviolet light. In warm countries, hours of work are often arranged so that workers can take a break, or even a siesta, during the hottest part of the day Scientists are working to discover the links between the weather and human beings' moods and performance.

It is generally believed that tempers grow shorter in hot, muggy weather. There is no doubt that 'crimes against the person' rise in the summer, when the weather is hotter and fall in the winter when the weather is colder. Research in the United States has shown a relationship between temperature and street riots. The frequency of riots rises dramatically as the weather gets warmer, hitting a peak around 27-30°C. But is this effect really due to a mood change caused by the heat? Some scientists argue that trouble starts more often in hot weather merely because there are more people in the street when the weather is good. Psychologists have also studied how being cold affects performance. Researchers compared divers working in icy cold water at 5°C with others in water at 20°C (about swimming pool temperature). The colder water made the divers worse at simple arithmetic and other mental tasks.

Psychologists have conducted studies showing that people become less sceptical and more optimistic when the weather is sunny. However, this apparently does not just depend on the temperature. An American psychologist studied customers in a temperature-controlled restaurant. They gave bigger tips when the sun was shining and smaller tips when it wasn't, even though the temperature in the restaurant was the same. A link between weather and mood ismade believable by the evidence for a connection between behavior and the length of the daylight hours. This in turn might involve the level of a hormone called melatonin, produced in the pineal gland in the brain. The amount of melatonin falls with greater exposure to daylight. Research shows that melatonin plays an important part in the seasonal behaviour of certain animals. For example, food consumption of stags increases during the winter, reaching a peak in February/March. It falls again to a low point in May, then rises to a peak in September, before dropping to another minimum in November. These changes seem to be triggered by varying melatonin levels.

 

 

Post-reading tasks

Look through the text to see if your guess was right. Is the head misleading?

 

Choose the synonyms according to the context.

 

1. Gloomy                         a) have none or insufficient of

2. Depression                    b) disturbance of the peace

3. Lack                              c) miserable

4. Performance                  d) oppressively damp and warm

5. Muggy                           e) mood of hopelessness

6. Riot                               f) carrying out, doing

 

Complete the following sentences.

1. Gloomy weather can be the reason for … .

2. To avoid SAD sufferers are recommended to ... .

3. Research in the United States has shown the higher is the temperature … .

4. Customers in a temperature-controlled restaurant give bigger tips when … .

5. The amount of melatonin depends on … .

 

 

Put the jumbled sentences in the logical order.

1. Divers perform much worse when they work in cool water.

2. The frequency of street riots rises dramatically as the weather gets warmer.

3. Melanin plays an important part in the seasonal behavior of certain animals.

4. The dull weather of winter reduces the amount of sunlight which affects some people.

5. Some people need exposing the light of full-spectrum lamps.

 

UNIT XXVIII

Key words and expressions: to dump, to dispose of, recycle, sewage, wasteful, rubbish, to pollute, nuclear waste, poisonous, to produce.

Dumping or Disposal

 

We often talk about waste disposal, but disposal is really the wrong word, because you cannot really dispose of waste. Suppose that you put your waste on a rubbish dump. You have dumped it, but you have not disposed of it.

If you want to do something better than dumping, you can change waste into something different. For example, you can burn it. This will produce heat, which may be useful, but it may also produce poisonous smoke and gases, which are another kind of waste.

Better still, you can change waste into something useful. This is called recycling. For example, old newspapers can be made into new paper.

Industry - making things for people to use - produces a lot of waste. Some industrial waste is just dirty, but some is actually dangerous. Some factories, for example, produce poisonous gases which go up into the air and then make acid rain which kills trees and pollutes water.

Sometimes toxic chemicals leak into rivers, polluting the water and killing fish and other animals. Toxic chemicals can also pollute the ground. In the USA in the 1930s, a chemical factory dumped a large number of big metal drums of waste chemicals in a hole in the ground. Later a builder covered the place with earth and built a small town called Love Canal there. In the 1970s the drums began to leak into the earth. The trees died. The ground was covered with a horrible, smelly, black slime which burned holes in people's shoes. Everybody had to leave Love Canal.

Later eighty-two different toxic chemicals were found in the earth.

There are billions of old tyres on dumps all over the world. Some years ago, fourteen million tyres on a dump in Canada caught fire. The fire burned for two weeks. The burning tyres produced a black, oily smoke and toxic gases, and left behind a poisonous black slime.

Power stations produce electricity for homes and shops, schools and factories. Many power stations also produce smoke, toxic gases, mountains of dirty black waste and acid rain. When nuclear power stations were first built, many people were pleased because they did not pollute like the old power stations. But nuclear power stations produce nuclear waste, which produces radiation. You cannot see or smell radiation, but it is very toxic - and it stays like that for thousands of years. You cannot easily dispose of nuclear waste. Until we discover a good way of disposing of nuclear waste we will have to live with this dangerous problem.

Waste from farms is a serious problem too. Farm animals produce a lot of dung. The chemicals from the dung can leak into the earth and poison it. They can also leak into rivers and poison the water.

Aeroplanes and cars, boats and buses produce poisonous gases which pollute the air. They also make a lot of noise, which is another kind of pollution. Perhaps the best answer to this problem is a quiet, clean bicycle!

People at home produce waste too, and rich countries are more wasteful than poor ones. Every day New York produces more than 24,000 tonnes of waste and a lot of it is sent by sea to dumps thousands of miles away.

Waste from toilets is called sewage. Millions of tonnes of sewage are dumped in the sea every year. The sewage pollutes the water, poisons fish and covers the beaches with brown slime.

 

 

Post-reading tasks