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steel tubular structure or in the form of reinforcement inside concrete. But obviously exposed
steel is unsuitable because of the problem of corrosion. So the question is, what’s the most
reliable way of protecting steel, over the long term? And we have to bear in mind that, just
because something requires regular maintenance, such as painting, that doesn’t necessarily
mean it’s unreliable. As long as the maintenance is consistent. The key question is, what’s the
most economical approach? So painting a steel structure every couple of years is uneconomical
only if the cost of painting is more expensive than the additional cost of using concrete at the
time of construction.
Mike: So, to determine the most efficient solution, we need to assess the lifespan of a reinforced
concrete structure. If we know that, we can determine how many times the equivalent steel
structure would need to be repainted over that same period, and what the cost of that would be.
Hanif: Yeah.
Mike: But this is really the point I'm making, Hanif. We can't categorically say that reinforced
concrete is inefficient unless we look into it in detail.
Hanif: Of course not. Look, let me make a suggestion ...

b Match the words (1-6) from the discussion to the definitions (a-f).
11 appropriate/suitable
12 consistent/reliable
13 cost-effective/economical
14 effective
15 efficient
16 sufficient/adequate

a the right solution for a particular situation
b good enough for the intended function
c performs a function well
d works quickly and well
e makes the most of resources, isn't wasteful
f doesn't break down, always performs in the same way

c Make the following words negative by adding the prefixes in- or un-.
19 adequate inadequate
20 appropriate
21 consistent
22 economical
23 effective
• efficient
• reliable
• sufficient
• suitable

d ► l0.1 Listen again. What issues do Mike, Loreta and Hanif agree and disagree on?
3a The following information is from the web site of Sigma Power, a firm that advises
corporate and government clients on wind energy projects. Complete the text using the
words in Exercise 2c.

Wind Turbines - FACT FILE
The fact that wind turbines consume no fuel and waste very little energy is clearly a fundamental
advantage. But just how efficient_ are they? Kev figures
93