Cambridge ielts 1-15 series reading answers explained

21. Answer: tuberculosis
Explain
He calculated that … in the air coming from patients suffering from … would not have harmed 
other patients.
·
Key words: calculated, air, patients, suffering, harmed, other patients
· In the last sentence of paragraph D, Short explained his findings: “We put pathogens in the 
airstreams, modeled for someone with tuberculosis … the ventilation systems in the room would have 
kept other patients safe from harm”. So, patients with tuberculosis (TB) would release pathogens in the 
air when they coughed – these minute organisms would harm other patients unless there was good 
ventilation. Short modeled this in his experiment. The answer for 20 is “pathogens”. 
· The purpose of this experiment was to test whether the system could prevent TB pathogens from 
spreading. Therefore, it is clear that answer for question 21 would be “tuberculosis”. 
22. Answer: wards
Explain
He also found that the air in … in hospitals could change as often as in a modern operating theatre.
·
Key words: air, hospitals, change, often modern operating theatre
· The first sentence of paragraph E states that “19th-century hospital wards could generate up to 24 
air changes an hour – that‟s similar to the performance of a modern-day, computer-controlled 
operating theatre”. This 
means that the air in hospitals wards could change as often as in a modern operating theatre. Thus, the 
word in the blank is “wards”. 
·
Answer: wards
23. Answer: communal
Explain
He suggests that energy use could be reduced by locating more patients in … areas.
·
Key words: energy, reduced, locating, patients,
· In the middle of paragraph E, Short states that communal wards “would work just as well…at a 
fraction of the energy cost”. “Communal wards” imply that more than one patient is located in each 
ward. “Fraction” implies that energy cost would be reduced, because less energy would be used. 
Therefore, the answer is “communal” areas.