TE
Tom Ellis
PW Paulina Weiler
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TEST 18
READING
IELTS 5 Practice Tests, Academic Set 4
Page 68
Questions 24 – 26
Label the diagram below.
Write NO MORE THAN THREE WORDS from the text for each answer.
Write your answers in boxes 24 - 26 on your answer sheet.
The Process of Icebergs Calving from a Glacier
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IELTS 5 Practice Tests, Academic Set 4
TEST 18
READING
Page 69
READING PASSAGE 3
You should spend about 20 minutes on Questions 27 - 40, which are based on Reading Passage 3
below.
Hybrid Cars
Most people these days are now aware of the real possibility of choosing to buy a hybrid car.
Hybrid electric vehicles (HEVs) are powered by an internal combustion engine or other propulsion
source that can be run on conventional or alternative fuel and an electric motor that uses energy
stored in a battery. HEVs combine the benefits of high fuel economy and low emissions with the
power and range of conventional vehicles. A wide variety of hybrid electric vehicles is currently
available. Although HEVs are often more expensive than similar conventional vehicles, some costs
may be recovered through fuel savings or state incentives. HEVs are powered by an internal
combustion engine and an electric motor, which uses energy stored in batteries. The extra power
provided by the electric motor allows for a smaller engine. Additionally, the battery can power
auxiliary loads like sound systems and headlights and reduce engine idling when stopped.
Together, these features result in better fuel economy without sacrificing performance.
HEVs can be either mild or full hybrids, and full hybrids can be designed in series or parallel
configurations. Mild hybrids, also called micro hybrids, use a battery and electric motor to help
power the vehicle and can allow the engine to shut off when the vehicle stops (such as at traffic
lights or in stop-and-go traffic), further improving fuel economy. Mild hybrid systems cannot
power the vehicle using electricity alone. These vehicles generally cost less than full hybrids, but
provide less substantial fuel economy benefits than full hybrids. Full hybrids have more powerful
electric motors and larger batteries, which can drive the vehicle on just electric power for short
distances and at low speeds. These systems cost more than mild hybrids, but provide better fuel
economy benefits.
There are different ways to combine the power from the electric motor and the internal
combustion engine. Parallel hybrids, for example, the most common HEV designs, can connect the
internal combustion engine and the electric motor to the wheels through mechanical coupling.
Both the electric motor and the internal combustion engine drive the wheels directly. Series
hybrids, on the other hand, use only the electric motor to drive the wheels and are sometimes
found in plug-in hybrid electric vehicles.
Hybrid cars have been around longer than most people realise. A man by the name of
Goldsworthy Gurney invented a steam car in 1825, which made an 85-mile road trip in ten hours.
In 1897, the London Electric Cab Company produced a fleet of cars known as the Bersey Cabs. This
fleet was powered by a 40-cell battery and a three horsepower electric motor. Around the same
time, the Pope Manufacturing Company of Hartford, Connecticut, manufactured approximately
500 electric cars over 2 years. Within the first few years of the twentieth century, thousands of
electric and hybrid cars were manufactured, but when Henry Ford introduced the assembly line
approach to manufacturing cars along with the technology to produce a self-starting engine, the
hybrid concept quickly declined.
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TEST 18
READING
IELTS 5 Practice Tests, Academic Set 4
Page 70
The discussion of whether to buy a hybrid car revolves around a variety of issues. Firstly, a country
that had a large number of hybrid cars would be less reliant on imported petroleum, which would
increase the country’s energy security. Last year, for example, the United States imported about
thirty-three per cent of the petroleum it consumed, and transportation was responsible for nearly
three-quarters of total U.S. petroleum consumption. With much of the world’s petroleum reserves
located in politically volatile countries, the United States is vulnerable to price spikes and supply
disruptions. This has led many countries’ governments to offer incentives to people owning a
hybrid car.
Another advantage of HEVs is that they achieve better fuel economy and have lower fuel costs
than similar conventional vehicles, although because they rely in whole or part on electric power,
their fuel economy is measured differently than in conventional vehicles. It must be taken into
account that the fuel economy of HEVs is highly dependent on the load carried and the duty cycle,
but in the right applications, they can maintain a strong fuel-cost advantage over their
conventional counterparts.
The environmental issue is often a deciding factor for those deciding about a hybrid car. Hybrid
and plug-in electric vehicles can have significant emissions benefits over conventional vehicles.
HEV emissions benefits vary by car model and type of hybrid power system. HEV’s also produce
no tailpipe emissions when in all-electric mode.
One deterrent for people considering the purchase of a hybrid car is that retail prices are more
expensive. While hybrids can save a lot of money on petrol, making the initial investment is often
a bit more than some people are willing to make up front. A better way to look at it is as an
investment in the future of our planet. People will also realise that they will recoup the difference
over time and in the long run save money.
Another negative side for hybrid ownership is the fact that when a hybrid car is in an accident, it is
more difficult for rescuers to get people out of the car due to the electric motor and the increased
risk of electrocution. The cost of a replacement battery for hybrid cars has also been a concern in
the past, with replacements costing thousands of dollars. It should be taken into consideration
that these hybrid battery packs are made to last for the life of the car and the warranty covers
batteries for somewhere between eight and ten years. The real concern with the batteries for
many environmentally conscious folk is toxicity upon disposal. This does not need to be a concern
nowadays, however, because most hybrids manufactured today use batteries that can be recycled
without a problem.
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IELTS 5 Practice Tests, Academic Set 4
TEST 18
READING
Page 71
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