Proyecto arquitectónico

Today, finding a source of fresh water is becoming more and more difficult. Many of our streams, rivers and lakes have been contaminated with sewage, and many towns and cities obtain their drinking water from these same streams, rivers and lakes. To prevent 5 this constant contamination, sewage treatment plants are being built in many places. These are capable of converting sewage into pure drinkable water.

Another way to solve the problem of fresh water is to make use of the most abundant source of water we have: the sea. If we could learn 10 to get potable water from sea water easily and cheaply, we would solve the problem. Man cannot live on sea water directly because of the high proportion of minerals (mainly salt) in it. More than 2% of salt in a solution is dangerous for the human body. Sea water contains 3.5% of salt. Such a high quantity causes dehydration in human body; 15 that is, the body loses the liquids necessary for life. Thus, it is

necessary to reduce the percentage of salt in sea water to an acceptable level before using n. A number of methods can be used to do this. The most common method is distillation. Sea water is heated until the water evaporates and the salt is left behind. The steam then condenses 20 into pure water. Another method is freezing. When this is done, the

water freezes first, leaving the salt behind. The ice is then removed and pure water is obtained. A third method is called reverse osmosis. Pure water molecules are separated from the salt molecules under great pressure.

25 Recently scientists have been working on a completely new idea: The idea of obtaining fresh water from the air. Winds coming from the sea carry a lot of water vapour. This vapour condenses into water if it strikes something cold. If scientists can build a large condenser, then they can collect and store fresh water easily. Unfortunately, the main 30 problem with all of the mentioned methods is their high cost. That's

why scientists are looking for ways of reducing the cost.

A. What do the following refer to? 1. These' (line 6):

2. 'it' (line 17):

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MINERALS

Minerals are substances which are crystalline solids and which occur naturally. There are more than twenty different minerals in the body. Three of the most important minerals are calcium, phosphorus, and iron. Calcium and phosphorus work together. The bony skeletons of vertebrate animals, including man, are composed of calcium phosphate. If people have enough calcium and phosphorus, their bones and teeth will be strong and hard. In addition, their muscles, nerves, and heart will work properly. Calcium makes up about 2% of the human body. About 99% of that amount is contained in the teeth and bones. Milk and hard cheeses are the best sources of calcium. After the age of 19, people need only 400 to 500 milligrams of calcium a day. Phosphorus, on the other hand, makes up 1.1% of the human body. A number of high-energy compounds found in our bodies, such as adenosine triphosphate (ATP), contain phosphorus. ATP is capable of transferring as well as storing energy in living cells and is responsible for energy necessary for physical activity.

Iron is a mineral which makes the blood look red and which carries oxygen for our normal physical activities. All lean meats - especially liver - whole grains, nuts, some vegetables, and dried fruits are good sources of this mineral. Iron deficiency results in a disease called anemia. Anemic people do not have enough iron in their blood, and this causes their hearts to beat faster so that their bodies can get more oxygen. Such people, therefore, get tired easily, and their skins sometimes look rather white.

A.

1. What two criteria does a subtance have to fulfill in order to be called a 'mineral'?

a)

b)

2. What are the minerals absolutely essential for our bodies?

3. What does deficiency in calcium and phosphorus cause in a person's body?

a)

4. Where does the body store most of the calcium?

5. What type(s) of minerals do people need if they want to have sufficient energy to play tennis, for instance?

6. How much calcium does a

a) fifteen-year-old person need? b) thirty-year-old person need? a)

b)

B. Complete the following according to the information in the passage. 1. Iron is essential in blood because

2. are food items rich in calcium. 3. Anemia is caused

4. An anemic person may show certain symptoms or signs. Two of these are: a)

b)

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A MISUNDERSTANDING

One of those misunderstandings which sometimes occurs when the gasman comes to call has brought puzzlement and ultimate good fortune into the domestic lives of two Essex women. Mrs. May Bradbrook and Mrs. Brenda Kerr live in Alton Gardens, Westcliff-on 5 -Sea. Mrs. Bradbrook's home is number 40 and the Kerr residence is number 14. The difficulties began when Mrs. Bradbrook decided that the time had come to purchase a new cooker. She placed her order with the North Thames Gas Board, but the official who took the details misheard her address.

10 Paperwork duly went through for the delivery and installation of a new gas cooker at number 14, Alton Gardens. When the gasmen arrived with it, there was nobody at home. They were relieved, however, to find a considerate note saying, "Key next door." Mrs.

Kerr was expecting a visit from the Eastern Electricity Board that day 15 and had made arrangements for a neighbour to let them in. When the gas board appeared instead, the neighbour assumed that she had misunderstood Mrs. Kerr and handed over the key. The new cooker was installed and Mrs. Kerr's old one taken away.

Shortly afterwards, an aggrieved Mrs. Bradbrook telephoned the 20 gas board saying that she had waited in all day but the cooker had not

come. Inquiries were started. Meanwhile, Mrs. Kerr got home to find • the unexpected and gleaming appliance in her kitchen. Clearly,

something was amiss but before Mrs. Kerr could get down to deciding how to sort it out, she had an urgent priority. She had to cook her 25 husband's tea. There was no other appliance in the house, so she used

the new cooker.

The board, having heard from Mrs. Bradbrook and contacted its gasmen, was swift to realise the error. It assured Mrs. Bradbrook that there would be no further delay in getting the cooker to her. After all, 30 it had only to travel a short way up the road.

But - Mrs. Bradbrook pointed out - it was no longer the new cooker she had ordered, was it? It had been used. The gas board saw her point and found that it also had a problem at number 14. It had assured Mrs. Kerr that her old cooker would be returned pronto. But it turned out 35 that the cooker had been broken up for scrap immediately after it was

taken away.

Both women had clearly suffered 'some inconvenience,' as the board acknowledged. The upshot of the affair is that Mrs. Bradbrook now has the cooker originally intended for her, but at a 20 per cent 40 discount of £30. Mrs. Kerr has been given a reconditioned "good as new" cooker worth an estimated £350 to replace her scrapped one. And the North Thames Gas Board is some £380 out of pocket.

A. Mark the best choice.

1. Line 19, 'aggrieved' means . a) upset b) confident c) tactful d) timed 2. Line 28, 'swift' means .

a) inquisitive b) gentle c) quick d) insensitive

3. Both Mrs. Bradbrook and Mrs. Kerr live in Alton Gardens and a mix-up occurred because .

a) Mrs. Bradbrook gave the wrong address to a gas board official b) Mrs. Kerr placed an order for a new gas cooker

c) someone at the gas board took the wrong message

d) Mrs. Bradbrook went out to work leaving a message next door for the gasmen

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