Cambridge ielts 1-15 series reading answers explained

 
16. Answer: v
Section C explains how the device works. It starts by emphasizing that “unlike standard desalination 
techniques, it (the desolenator) doesn‟t require a generated power supply: just sunlight”. This is 
considered the feature of the desolenator which makes it different from other alternatives. Thus, the 
heading is v – „What makes the device different from alternatives‟. 

different = unlike 
 
17. Answer: x
The topic sentence of Section D is right at the beginning: “A recent analysis found that at least two-
thirds of the world‟s population lives with severe water scarcity for at least a month every year”. The 
section then continues by describing the hardships in such regions with water shortage, with different 
vocabulary for the same phenomenon: “water scarcity”, “water stress”. So the correct heading must be 
x – „The number of people affected by water shortages‟. 

water shortage = water stress = water scarcity 
 
18. Answer: iv
This section names “a wide variety of users” for the desolenator, both in the developing and developed 
world. In the developing world, customers can be “those who cannot afford the money for the device 
outright and pay through microfinance, and middle-income homes that can lease their own 
equipment”. Meanwhile, potential markets in developed countries are “niche markets where tap water 
is unavailable”. Therefore, the most suitable heading for Section E would be iv – „The range of 
potential customers for the device‟. 

customers ~ users 
 
19. Answer: viii
This section discusses the price of the desolenator. Janssen said that his company has a “social 
mission” and that the main application would be in “the developing world and humanitarian sector”. 
By saying “this is the way we will proceed”, Janssen implies that the company will proceed to produce 

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devices that can help those in need. Thus, it can be inferred that profit is not the primary goal for 
Janssen. The answer is viii.