9
The diagrams explain how cement is made through different stages and its use
in the production of concrete. Overall, there are five main stages in the cement-
making process, commencing with crushing two
main materials and ending
when ready cement is packaged. In concrete production, four different raw
materials and only one equipment are required.
Cement production starts when limestone and clay are crushed together,
resulting in their powder form. The powder, then, goes through a mixer, which
then directs it to rotating heater, a bigger turbine with an attached fire point, via
a pipe. Having been heated, the material arrives on a surface which moves on
a
conveyer, delivering it to the grinder point. At this phase, the pre-cement
material is grounded and turns
into what we call ‘cement’, which is then
packaged into special bags.
Regarding concrete making, there are four main ingredients that are necessary,
while only a concrete mixer can do the whole job. Gravel, small stones, make
up of a half of typical concrete, while a quarter belongs to sand. Despite being
of huge importance
in concrete production, the percentage of cement only
accounts for 15%, and the remaining a tenth goes for water. The process itself
is not quite sophisticated, in which all these materials are mixed together in the
mentioned equipment.
Word count: 217
#7 | May 1
10
Traffic congestion and increasing volume of smog have been two major
problems in both developed and developing parts of the world. While making
the cost of petrol more expensive can be one way, but not the best, of dealing
with
these issues, I believe upgrading public transport and encouraging
employees to telecommute could do the job better.
On the one hand, charging exorbitant prices for petrol can play a part in
reducing the number of cars on roads. If this cost went up towards the point
where it may not be quite
affordable for the public, motorists would be
discouraged from using their private cars, due in large part to avoiding high
spending on travelling. As a result, the flow of traffic would be much smoother,
saving both the time and nerves of commuters.
Fewer cars being used also
means less harmful gases, mainly carbon emissions, are released into the
atmosphere. Not only does this ensure that people
suffer less from certain
respiratory diseases, including asthma, but the contribution to the global
warming would be alleviated to a great degree.
Having said that, this method seems not be the key to the mentioned problems.
One more effective measure could be improving the state of public transport.
For example, having upgraded trams and buses with more comfortable seats,
news-spreading screens and AC units, the government in Sydney has attracted
more commuters to the use of these means of transportation, at the expense of
private cars. For another thing, employers should allow their staff to tele-work,
or to the least, commute back and forth in off-peak traffic times. These changes
in working practices coupled with flextime could
keep more cars off roads in
rush-hours, directly easing heavy traffic flow.
To sum up, increasing the price of petrol could address the problems of traffic
and pollution, but there appears to be more effective methods. While certain
improvements in public transportation can be one way, the other is
implementing the practice of remote working, along with flexible working hours,
for employees.
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