Reading Exercise: Cloud Seeding & Organic Food Insights | Môn English - Đại học Kinh Tế Quốc Dân

lOMoAR cPSD| 61200861 Exercise 1: The rain makers
Science and technology work with nature to bring rain when and where it is needed
A Wheat farmer Gang Liu is a worried man. The annual rains have not arrived, and there is a danger
that unless there is substantial rainfall soon, his annual wheat crop will fail. As he looks anxiously at
the clouds which promise rain but are failing to deliver it, there is a sudden loud roar, and from fields
for miles around, hundreds of small rockets are fired into the clouds. Within twenty minutes, the
farms around the eastern Chinese city of Luohe are experiencing their first rain for many weeks. Gang
Lius valuable wheat has been saved, thanks to a technique known as 'cloud seeding, in which the
chemical silver iodide (Agl) is introduced into clouds. This causes the tiny drops of moisture in the
clouds to turn to ice. These tiny ice particles join until they become heavy enough to fall from the sky,
turning into rain as they melt.
B But did cloud seeding really cause the rain in Luohe to fall, or was just a coincidence? Experts often
question whether cloud seeding actually works. It is hard to tell how effective cloud seeding actually
is, they say, as it might have rained anyway, without human intervention. But this has not stopped
many governments and organisations from trying. There are currently 150 weather-modifying
projects taking place in more than 40 countries. Not all of them are aimed at creating rain. The
Eastlund Scientific Enterprises Corporation in the USA, for example, is experimenting with firing
microwaves into clouds to prevent the tornadoes which cause enormous damage to the country
every year. In Russia, experiments have been carried out to make sure the sun shines during
important national events.
C However, It is rainmaking that dominates the research programmes. In many of these, researchers
are using trials in which some clouds are 'seeded' while others are not, and both groups are
monitored. Arlen Huggins of the Desert Research Institute is leading a research project in Australia.
Weather-monitoring technology is so good nowadays, he says, that we can measure clouds mụch
more effectively, even from the inside. As a result, we now know mụch more about the effect humans
can have on the weather. What Huggins' team has discovered so far is promising. They believe that
cloud seeding does work, although there are still two years of the six-year project left to go.
D In China, where the majority of cloud-seeding operations take place, weather-modification
authorities use army rockets to fire silver-iodide particles into the clouds. 59,000 staff working for the
China Meteorological Administration (CMA) are equipped with 7,115 army cannons which, in 2006,
were used to fire a million silver-Iodide rockets into the atmosphere. This costs over $100 million a
year, although the CMA claims the results are worth the expense. Between 1999 and 2006, they say,
cloud seeding produced 250 billion metric tonnes of rain and prevented thousands of farmers from losing their crops.
E We want to understand what makes clouds rain,“ says Philip Brown of the UK Meteorological office,
explaining why so much time, effort and money are being invested. “But there is a more powerful
economic reason. A lot of countries around the world are at risk from drought, and governments will
try anything to make sure that doesn’t happen, even if the scientific evidence is weak. The potential
economic value is greater than the scientific value. Making it rain might allow you to keep agriculture
going where, without human intervention, it might fail”.
F Some people are concerned, however, that altering the weather can have negative consequences. lOMoAR cPSD| 61200861
Leonard Barrie, director of the research department at the World Meteorological Organisation in
Geneva, explains why. “All areas of weather modification are still very controversial. Some people think
that diverting water for irrigation benefits some people, but ís a disadvantage to others.
Someone in one area will get more water, but as a result, someone somewhere else could get less“. His
fears may be justified. Recently, the town of Zhoukou in China’s Henan province accused neighbouring
town Pingdingshang of “stealing' rain from clouds that were due to pass over its own farms, prompting
what may be the world very first documented incident of 'rain rage’.
Source: Complete IELTS band 4-5 1. iv 2. ix 3. vii 4. i 5. iii 6. vi lOMoAR cPSD| 61200861 Exercise 2:
Whale communication A
It is only comparatively recently that we have become aware of the hauntingly beautiful
sounds made by humpback whales. The hydrophone, a microphone that can be used in water, was
developed by the British scientist Ernest Rutherford, and is particularly good at detecting the presence
of submarines underwater. During the Cold War, a Bermudian, Frank Watlington was working for the
US government, and it was his job to use hydrophones to listen out for Russian submarines. While he
was doing this, Watlington noticed that humpback whales appeared to 'sing'. Later, Watlington's work
was taken up by two other researchers, Roger Payne and Scott McVay, who studied the nature of these
humpback whale 'songs'. They found that the various sounds produced by the whale formed a song
which lasts for about 30 minutes and is then repeated by the whale for hours or even days. B
Scientists believe there are two main reasons for whales to make sounds: echolocation, so that
the whales know what objects (and perhaps food) are around them; and communication. Whales are
capable of communicating to other whales over huge distances. Sound waves travel faster through
water (around 1.5 kilometre per second) than through air, and the sound of a whale can travel
thousands of kilometres through the oceans C
Many different species of whale are capable of making noises and some of them (as well as
dolphins and porpoises) are believed to use echolocation. Some whales look for food, such as squid,
down to a depth of 1.5 kilometres, and at that depth there is virtually no light at all. Without being
able to locate their food, the whales are going to go hungry. The whales send out series of clicks and
listen out for the echo of the sound. From this, the whale is able to work out what is around it and can
respond accordingly. The system whales use is highly complex, but it is similar to the way that you can
tell direction of sound. You have two ears and when a sound is made, the sound reaches one ear a
fraction of a second before the other. From this information, your brain can work out the direction of the sound. D
In addition to echolocation, some whales, most notably the humpback whale, are capable of
producing a range of notes which appear to be a form of communication. Humpback whales in one
school (as groups of whales are known) tend to sing virtually the same song. Perhaps like football
supporters they are demonstrating group identity, showing that they belong to the same school. Other
schools, particularly those found in other oceans, sing songs which are quite different. It is also quite
likely that the songs play a role in courtship. It is generally the males that sing, so perhaps they are
also trying to attract females. E
For millions of years, whales have swum in the great oceans of the world and only recently
have they had to contend with a predator: man. In the 18th and 19th centuries, many countries had
fleets of ships which set out to bring back whales. The 20th century saw the development of factory
ships which were capable of killing and processing thousands of whales. In the 1930s, over 50,000
whales were killed annually. It wasn't until 1986 that a moratorium was agreed to stop whale hunting,
and scientists hope that the number of whales will recover. So can the whales of the world now cruise
about without a care in the world? Sadly not. The growth of trade in the world has meant that there
are now more ships, particularly large container ships, than ever before. In fact, the Worldwide Fund
for Nature (WWF) says that large numbers of northern right whales are killed in collision with ships. lOMoAR cPSD| 61200861
But it is not only the physical danger that ships present. The loud noises of ships' engines are very likely
to disturb the whales, and the WWF have called for shipping restrictions in certain areas. F
In recent years, there have been many cases of whales dying on beaches. Could the reason for
these tragedies have something to do with the noise pollution that these majestic creatures have to
live with? There is no definite answer to the question, but it has attracted considerable research, and
findings seem to point to man's industrial activities in the ocean. With an ever-growing need for oil,
more and more drilling takes place offshore. To assess the likelihood of the presence of oil,
seismologists use sonar to work out the underlying geology. The sounds used in such tests are believed
by some people to have a highly damaging effect on whales, either simply disrupting their method of
communication, or, some scientists believe, actually killing them. With an ever-increasing human
population and dwindling resources, whales face an uncertain future. While it is unlikely that we will
ever know exactly why whales producing their whale songs, the world will be a much poorer place without them.
Source: IELTS Advantage - Reading skills F. iv G. iii B. Ix C. lOMoAR cPSD| 61200861 Exercise 3:
Organic food: why? by Rob
Lyons and Jan Bowman A
Today, many governments are
promoting organic or natural
farming methods that avoid the
use of pesticides and other
artificial products. The aim is to
show that they care about the environment and about
people's health. But is this the
right approach? A Europe is
now the biggest market for
organic food in the world,
expanding by 25 percent a year
over the past 10 years. So what
is the attraction of organic food
for some people? The really
important thing is that organic
sounds more 'natural'. Eating
organic is a way of defining
oneself as natural, good, caring,
different from the junkfood- scoffing masses. As one
journalist puts it: 'It feels closer
to the source, the beginning, the
start of things.' The real desire is
to be somehow close to the soil, to Mother Nature. B
Unlike conventional farming, the organic approach means farming with natural, rather than
manmade, fertilisers and pesticides. Techniques such as crop rotation improve soil quality and help lOMoAR cPSD| 61200861
organic farmers compensate for the absence of man-made chemicals. As a method of food production,
organic is, however, inefficient in its use of labour and land; there are severe limits to how much food
can be produced. Also, the environmental benefits of not using artificial fertiliser are tiny compared
with the amount of carbon dioxide emitted by transporting food (a great deal of Britain's organic
produce is shipped in from other countries and transported from shop to home by car). C
Organic farming is often claimed to be safer than conventional farming - for the environment
and for consumers. Yet studies into organic farming worldwide continue to reject this claim. An
extensive review by the UK Food Standards Agency found that there was no statistically significant
difference between organic and conventional crops. Even where results indicated there was evidence
of a difference, the reviewers found no sign that these differences would have any noticeable effect on health. D
The simplistic claim that organic food is more nutritious than conventional food was always
likely to be misleading. Food is a natural product, and the health value of different foods will vary for
a number of reasons, including freshness, the way the food is cooked, the type of soil it is grown in,
the amount of sunlight and rain crops have received, and so on. Likewise, the flavour of a carrot has
less to do with whether it was fertilised with manure or something out of a plastic sack than with the
variety of carrot and how long ago it was dug up. The differences created by these things are likely to
be greater than any differences brought about by using an organic or nonorganic system of production.
Indeed, even some 'organic' farms are quite different from one another. E
The notion that organic food is safer than 'normal' food is also contradicted by the fact that
many of our most common foods are full of natural toxins. Parsnips cause blisters on the skin of
agricultural workers. Toasting bread creates carcinogens. As one research expert says: 'People think
that the more natural something is, the better it is for them. That is simply not the case. In fact, it is
the opposite that is true: the closer a plant is to its natural state, the more likely it is that it will poison
you. Naturally, many plants do not want to be eaten, so we have spent 10,000 years developing
agriculture and breeding out harmful traits from crops.' F
Yet educated Europeans are more scared of eating traces of a few, strictly regulated, man-
made chemicals than they are of eating the ones that nature created directly. Surrounded by plentiful
food, it's not nature they worry about, but technology. Our obsessions with the ethics and safety of
what we eat - concerns about antibiotics in animals, additives in food, GM crops and so on- are
symptomatic of a highly technological society that has little faith in its ability to use this technology
wisely. In this context, the less something is touched by the human hand, the healthier people assume it must be G
Ultimately, the organic farming movement is an expensive luxury for shoppers in well-
manicured Europe. For developing parts of the world, it is irrelevant. To European environmentalists,
the fact that organic methods require more labour and land than conventional ones to get the same
yields is a good thing; to a farmer in rural Africa, it is a disaster. Here, land tends to be so starved and
crop yields so low that there simply is not enough organic matter to put back into the soil. Perhaps the
focus should be on helping these countries to gain access to the most advanced farming techniques,
rather than going back to basics. " lOMoAR cPSD| 61200861
Source: Complete IELTS band 5.5 - 6.5 B.v C.i D.iii E.ix F.vii G.iv