…………………
.
24
…………………
in humans is associated with limbic disruption.
25
An industrial accident caused Phineas Gage to lose part of his
…………………
.
26
After his accident, co-workers noticed an imbalance between Gage’s
…………………
and higher-order thinking.
© The British Council 2012. All rights reserved.
11
READING PASSAGE 3
You should spend about 20 minutes on
Questions 27–40
, which are based on Reading
Passage 3 below.
HELIUM’S FUTURE UP IN THE AIR
A
In recent years we have all been exposed to dire media reports concerning the
impending demise of global coal and oil reserves, but the depletion of another key
non-renewable resource continues without receiving much press at all. Helium – an
inert, odourless, monatomic element known to lay people as the substance that makes
balloons float and voices squeak when inhaled – could be gone from this planet within
a generation.
B
Helium itself is not rare; there is actually a plentiful supply of it in the cosmos.
In fact, 24 per cent of our galaxy’s elemental mass consists of helium, which makes it
the second most abundant element in our universe. Because of its lightness, however,
most helium vanished from our own planet many years ago. Consequently, only a
miniscule proportion – 0.00052%, to be exact – remains in earth’s atmosphere.
Helium is the by-product of millennia of radioactive decay from the elements thorium
and uranium. The helium is mostly trapped in subterranean natural gas bunkers and
commercially extracted through a method known as fractional distillation.
C
The loss of helium on Earth would affect society greatly. Defying the
perception of it as a novelty substance for parties and gimmicks, the element actually
has many vital applications in society. Probably the most well known commercial
usage is in airships and blimps (non-flammable helium replaced hydrogen as the
lifting gas
du jour
after the Hindenburg catastrophe in 1932, during which an airship
burst into flames and crashed to the ground killing some passengers and crew). But
helium is also instrumental in deep-sea diving, where it is blended with nitrogen to
mitigate the dangers of inhaling ordinary air under high pressure; as a cleaning agent
for rocket engines; and, in its most prevalent use, as a coolant for superconducting
magnets in hospital MRI (magnetic resonance imaging) scanners.
D
The possibility of losing helium forever poses the threat of a real crisis
because its unique qualities are extraordinarily difficult, if not impossible to duplicate
(certainly, no biosynthetic ersatz product is close to approaching the point of
feasibility for helium, even as similar developments continue apace for oil and coal).
Helium is even cheerfully derided as a “loner” element since it does not adhere to
other molecules like its cousin, hydrogen. According to Dr. Lee Sobotka, helium is
the “most noble of gases, meaning it’s very stable and non-reactive for the most part
© The British Council 2012. All rights reserved.
12
… it has a closed electronic configuration, a very tightly bound atom. It is this
coveting of its own electrons that prevents combination with other elements’. Another
important attribute is helium’s unique boiling point, which is lower than that for any
other element. The worsening global shortage could render millions of dollars of
high-value, life-saving equipment totally useless. The dwindling supplies have
already resulted in the postponement of research and development projects in physics
laboratories and manufacturing plants around the world. There is an enormous supply
and demand imbalance partly brought about by the expansion of high-tech
manufacturing in Asia.
E
The source of the problem is the Helium Privatisation Act (HPA), an
American law passed in 1996 that requires the U.S. National Helium Reserve to
liquidate its helium assets by 2015 regardless of the market price. Although intended
to settle the original cost of the reserve by a U.S. Congress ignorant of its
ramifications, the result of this fire sale is that global helium prices are so artificially
deflated that few can be bothered recycling the substance or using it judiciously.
Deflated values also mean that natural gas extractors see no reason to capture helium.
Much is lost in the process of extraction. As Sobotka notes: "[t]he government had the
good vision to store helium, and the question now is: Will the corporations have the
vision to capture it when extracting natural gas, and consumers the wisdom to
recycle? This takes long-term vision because present market forces are not sufficient
to compel prudent practice”. For Nobel-prize laureate Robert Richardson, the U.S.
government must be prevailed upon to repeal its privatisation policy as the country
supplies over 80 per cent of global helium, mostly from the National Helium Reserve.
For Richardson, a twenty- to fifty-fold increase in prices would provide incentives to
recycle.
F
A number of steps need to be taken in order to avert a costly predicament in
the coming decades. Firstly, all existing supplies of helium ought to be conserved and
released only by permit, with medical uses receiving precedence over other
commercial or recreational demands. Secondly, conservation should be obligatory and
enforced by a regulatory agency. At the moment some users, such as hospitals, tend to
recycle diligently while others, such as NASA, squander massive amounts of helium.
Lastly, research into alternatives to helium must begin in earnest.
© The British Council 2012. All rights reserved.
13
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