Reading for IELTS - practice test without answer PDF

Preview

Summary

This is an authentic test which was taken in December 2019...

Description

PASSAGE 1: Crop-growing skyscrapers By the year 2050, nearly 80% of the Earth's population will live in urban centres. Applying the most conservative estimates to current demographic trends, the human population will increase by about three billion people by then. An estimated 10 hectares of new land (about 20% larger than Brazil) will be needed to grow enough food to feed them, if traditional farming methods continue as they are practised today. At present, throughout the world, over 80% of the land that is suitable for raising crops is in use. Historically, some 15% of that has been laid waste by poor management practices. What can be done to ensure enough food for the world's population to live on? The concept of indoor farming is not new, since hothouse production of tomatoes and other produce has been in vogue for some time. What is new is the urgent need to scale up this technology to accommodate another three billion people. Many believe an entirely new approach to indoor farming is required, employing cutting-edge technologies. One such proposal is for the 'Vertical Farm'. The concept is of multi-storey buildings in which food crops are grown in environmentally controlled conditions. Situated in the heart of urban centres, they would drastically reduce the amount of transportation required to bring food to consumers. Vertical farms would need to be efficient, cheap to construct and safe to operate. If successfully implemented, proponents claim, vertical farms offer the promise of urban renewal, sustainable production of a safe and varied food supply (through year-round production of all crops), and the eventual repair of ecosystems that have been sacrificed for horizontal farming. It took humans 10,000 years to learn how to grow most of the crops we now take for granted. Along the way, we despoiled most of the land we worked, often turning verdant, natural ecozones into semi-arid deserts. Within that same time frame, we evolved into an urban species, in which 60% of the human population now lives vertically in cities. This means that, for the majority, we humans have shelter from the elements, yet we subject our food-bearing plants to the rigours of the great outdoors and can do no more than hope for a good weather year. However, more often than not now, due to a rapidly changing climate, that is not what happens. Massive floods, long droughts, hurricanes and severe monsoons take their toll each year, destroying millions of tons of valuable crops. The supporters of vertical farming claim many potential advantages for the system. For instance, crops would be produced all year round, as they would be kept in artificially controlled, optimum growing conditions. There would be no weather-related crop failures due to droughts, floods or pests. All the food could be grown organically, eliminating the need for herbicides, pesticides and fertilisers. The system would greatly reduce the incidence of many infectious diseases that are acquired at the agricultural interface. Although the system would consume energy, it would return energy to the grid via methane generation from composting non-edible parts of plants. It would also dramatically reduce fossil fuel use, by cutting out the need for tractors, ploughs and shipping. A major drawback of vertical farming, however, is that the plants would require artificial light. Without it, those plants nearest the windows would be exposed to more sunlight and grow more quickly, reducing the efficiency of the system. Single-storey greenhouses have the benefit of natural overhead light: even so, many still need artificial lighting. A multi-storey facility with no

natural overhead light would require far more. Generating enough light could be prohibitively expensive, unless cheap, renewable energy is available, and this appears to be rather a future aspiration than a likelihood for the near future. One variation on vertical farming that has been developed is to grow plants in stacked trays that move on rails. Moving the trays allows the plants to get enough sunlight. This system is already in operation, and works well within a single-storey greenhouse with light reaching it from above: it is not certain, however, that it can be made to work without that overhead natural light. Vertical farming is an attempt to address the undoubted problems that we face in producing enough food for a growing population. At the moment, though, more needs to be done to reduce the detrimental impact it would have on the environment, particularly as regards the use of energy. While it is possible that much of our food will be grown in skyscrapers in future, most experts currently believe it is far more likely that we will simply use the space available on urban rooftops. Questions 1-7 Complete the sentences below. Choose NO MORE THAN TWO WORDS from the passage for each answer. Write your answers in boxes 1-7 on your answer sheet. Indoor farming 1 Some food plants, including …………., are already grown indoors. 2 Vertical farms would be located in ……………, meaning that there would be less need to take them long distances to customers. 3 Vertical farms could use methane from plants and animals to produce ………….. 4 The consumption of ……………..would be cut because agricultural vehicles would be unnecessary. 5 The fact that vertical farms would need ………………. light is a disadvantage. 6 One form of vertical farming involves planting in ……………… which are not fixed. 7 The most probable development is that food will be grown on ……………. in towns and cities.

PASSAGE 2: Tough Sensor Can Take the Heat

A. A new gas sensor made from a nickel's worth of materials can endure high temperatures, corrosion, vibrations, and exposure to water, according to its inventors at Argonne National Laboratory in Illinois. The tiny sensor detects a variety of gases.

B. Conventional silicon sensors do not work well at temperatures above 150°F. But Argonne's new sensor, made of ceramics and metals, is not affected by high temperatures. "The materials in this sensor behave well through a wide range of temperatures," says Michael Vogt, a control systems engineer at Argonne. C. Vogt and his colleagues made the sensor by film screening layers of ceramic and metal on a ceramic substrate, then firing the sensor in an industrial oven at more than 1,000°C. The Argonne researchers set out to build a sensor that would detect overheating computer components. Before an overheating component fails, and possibly ignites, epoxy in the circuit boards releases a gas. The Argonne sensor can detect this vapour and cut off power to the circuit. D. The device senses gases by applying a steadily increasing voltage across its electrical leads and monitoring current spikes induced as gases react on the sensor's surface. Each gas reacts at a characteristic voltage, and the size of the current spike indicates the "signature" of several representative organic solvents. E. The sensor could be used to monitor hydrocarbon emissions from cars; today's typical sensors can only measure oxygen. The sensor could also monitor gases in industrial chemical processes. Question 8 - 11

Below is a table with information about the new gas sensor and conventional gas sensor. Fill in the missing information with NO MORE THAN THREE WORDS

Temperature at

Components Uses

which they work well New gas sensor

a wide range of

9.

temperature

monitor hydrogen emission from cars and gases in industrial, chemical processes

Conventional gas sensor

Question 12 - 17

8.

10.

11.

Below is a summary of a passage. Fill in the spaces with NO MORE THAN THREE WORDS from the passage

A new sensor made of ceramics and metals can endure corrosion, vibrations, exposure to water, and 12……………, while not affected by 13…………… As 14……………. reacts at a 15……………., the device applies a steadily increasing voltage and monitors current spikes induced, 16…………….. of which indicates the concentration of the gases. Conventional sensors, on the other hand, do not work well at temperatures above 150°F and could be used only to 17…………...

PASSAGE 3 The History Of The Tortoise If you go back far enough, everything lived in the sea. At various points in evolutionary history, enterprising individuals within many different animal groups moved out onto the land, sometimes even to the most parched deserts, taking their own private seawater with them in blood and cellular fluids. In addition to the reptiles, birds, mammals and insects which we see all around us, other groups that have succeeded out of water include scorpions, snails, crustaceans such as woodlice and land crabs, millipedes and centipedes, spiders and various worms. And we mustn’t forget the plants, without whose prior invasion of the land none of the other migrations could have happened. Moving from water to land involved a major redesign of every aspect of life, including breathing and reproduction. Nevertheless, a good number of thoroughgoing land animals later turned around, abandoned their hard-earned terrestrial re-tooling, and returned to the Water Seals have only gone part way back. They show us what the intermediates might have been like, on the way to extreme cases such as whales and dugongs. Whales (including the small whales we call dolphins) and dugongs, with their close cousins the manatees, ceased to be land creatures altogether and reverted to the full marine habits of their remote ancestors. They don‘t even come ashore to breed. They do, however, still breathe air, having never developed anything equivalent to the gills of their earlier marine incarnation. Turtles went back to the sea a very long time ago and, like all vertebrate returnees to the water, they breathe air. However, they are, in one respect, less fully given back to the water than whales or dugongs, for turtles still lay their eggs on beaches. There is evidence that all modem turtles are descended from a terrestrial ancestor which lived before most of the dinosaurs. There are two key fossils called Proganochelys quenstedti and Palaeochersis talampayensis dating from early dinosaur times, which appear to be close to the ancestry of all modern turtles and tortoises. You might wonder how we can tell whether fossil animals lived on land or in water, especially if only fragments are found. Sometimes it’s obvious. Ichthyosaurs were reptilian contemporaries of the dinosaurs, with fins and streamlined bodies. The fossils look like dolphins and they surely lived like dolphins, in the water. With turtles it is a little less obvious. One way to tell is by measuring the bones of their forelimbs.

Walter Joyce and Jacques Gauthier, at Yale University, obtained three measurements in these particular bones of 71 species of living turtles and tortoises. They used a kind of triangular graph paper to plot the three measurements against one another. All the land tortoise species formed a tight cluster of points in the upper part of the triangle; all the water turtles cluster in the lower part of the triangular graph. There was no overlap, except when they added some species that spend time both in water and on land. Sure enough, these amphibious species show up on the triangular graph approximately half way between the ‘wet cluster' of sea turtles and the ‘dry cluster' of land tortoises. 'The next step was to determine where the fossil fell. The bones of P. quenstedti and P. talampayensis leave us in no doubt. Their points on the graph are right in the thick of the dry cluster. Both these fossils were dry-land tortoises. They come from the era before our turtles returned to the water. You might think, therefore, that modern land tortoises have probably stayed on land ever since those early terrestrial times, as most mammals did after a few of them went back to the sea. But apparently not. If you draw out the family tree of all modern turtles and tortoises, nearly all the branches are aquatic. Today’s land tortoises constitute a single branch, deeply nested among branches consisting of aquatic turtles. This suggests that modern land tortoises have not stayed on land continuously since the time of P. quenstedti and P. talampayensis. Rather, their ancestors were among those who went back to the water, and they then re-emerged back onto the land in (relatively) more recent times. Tortoises therefore represent a remarkable double return. In common with all mammals, reptiles and binds, their remote ancestors were marine fish and before that various more or less wormlike creatures stretching back, still in the sea, to the primeval bacteria. Later ancestors lived on land and stayed there for a very large number of generations. Later ancestors still evolved back into the water and became sea turtles. And finally, they returned yet again to the land as tortoises, some of which now live in the driest of deserts.

Questions 18-21 Answer the questions below Choose NO MORE THAN TWO WORDS from the passage for each answer Write your answers in boxes 27-30 on your answer sheet. 18. What had to transfer from sea to land before any animals could migrate? 19. Which TWO processes are mentioned as those in which animals had to make big changes as they moved onto land? 20. Which physical feature. possessed by their ancestors, do whales lack? 21. Which animals might ichthyosaurs have resembled? Questions 22 - 27 Complete the flow-chart below Choose NO MORE THAN TWO WORDS AND/OR A NUMBER from the passage for each answer Write your answers in boxes 34-39 on your answer sheet.

Method of determining where the ancestors of turtles and tortoises come from

Step 1: 71 species of living turtles and tortoises were examined and a total of 22 ................were taken from the bones of their forelimbs. Step 2: The data was recorded on a 23 ................... (necessary for comparing the information). Outcome: Land tortoises were represented by a dense 24 .................. of points towards the top. Sea turtles were grouped together in the bottom part. Step 3: The same data was collected from some living 25 .................. species and added to the other results. Outcome: The points for these species turned out to be positioned about 26 .................. up the triangle between the land tortoises and the sea turtles. Step 4: Bones of P. quenstedti and P. talampayensis were examined in a similar way and the results added. Outcome: The position of the points indicated that both these ancient creatures were 27...................... Questions 28 Choose the correct letter A, B, C or D. Write the correct letter in box 40 on your answer sheet. According to the writer, the most significant thing about tortoises is that A. They are able to adapt to life in extremely dry environments. B. Their original life form was a kind of primeval bacteria, C. They have so much in common with sea turtles. D. They have made the transition from sea to land more than once....