Wendy Moore reviews Ed Yong's book on microbes. We carry more microbial cells than human ones, 'bad' microbes are just microbes in the wrong place, and only a few species cause disease. Obsessive hygiene, antibiotics and poor diets upset the balance, and the future may use microbes against dengue fever or build them into hospital walls.
The multiple choice (14-16) covers the first, second and fifth paragraphs. The summary (17-20) covers the sixth and seventh. YES / NO / NOT GIVEN (21-26) covers the last two paragraphs.
Multiple choice
Questions 14-16
How to attack this block: The first paragraph says microbes were here before animal life and 'will outlive us'. The second is impressed by 39 trillion microbial cells against 30 trillion human ones. The fifth tells how van Leeuwenhoek first saw them, which is how a discovery was made.
Question 14
Answer: DParagraph 1, first sentence
What does the writer say about microbes in the first paragraph?
Microbes, most of them bacteria, have populated this planet since long before animal life developed and they will outlive us.
Question says → Passage says
continue to exist for longer thanwill outlive
the human raceus
Why: To 'outlive' someone is to go on existing after they're gone. 'Us' means humans, so microbes will last longer than the human race. D.
The trap: C borrows the list 'from seaweed and coral to dogs and humans', but that list says microbes are in every form of life. It doesn't say they're more common in animals than plants. B is wrong too: 'we mess with them at our peril' says the risk is real, not exaggerated.
Question 15
Answer: CParagraph 2, second sentence
What impresses the writer in the second paragraph?
What is amazing is that while the number of human cells in the average person is about 30 trillion, the number of microbial ones is higher - about 39 trillion.
Question says → Passage says
the writer is impressed byWhat is amazing is
the average individualthe average person
more microbial cells than human onesthe number of microbial ones is higher
Why: 'What is amazing' is the writer telling you directly what impresses her: 39 trillion microbial cells against 30 trillion human ones. C.
The trap: A looks close because the paragraph opens with microbes varying 'between species'. But it says they vary, not that they're 'vastly different', and that isn't what the writer calls amazing. B is from the next paragraph (the right hand sharing a sixth of its microbes).
Question 16
Answer: AParagraph 5, second and third sentences
What is the writer doing in the fifth paragraph?
The first man to see these extraordinarily potent creatures was a Dutch lens-maker called Antony van Leeuwenhoek in the 1670s. Using microscopes of his own design
Question says → Passage says
a discoveryThe first man to see these… creatures
how… was madeUsing microscopes of his own design… he examined a drop of water
Why: Most of the paragraph tells the story of van Leeuwenhoek: who he was, the microscopes he built, the lake water he examined and the 'animalcules' he found. That's explaining how a discovery was made. A.
The trap: D is tempting because Pasteur's work 'indicated that some microbes caused disease'. But the paragraph only says that he found this, not how microbes cause it. B fails because no two theories are compared, and C because nobody is described as confused.
Summary completion (word list A-H)
Questions 17-20
How to attack this block: Fewer than a hundred species bring disease (illness), and the relationship is symbiotic (partnership). The growing problem is low-fibre diets (poor nutrition) and our obsession with hygiene (cleanliness).
Question 17
Answer: GParagraph 6, first sentence
What do only a small number of microbes lead to?
while fewer than one hundred species of bacteria bring disease, many thousands more play a vital role in maintaining our health
Question says → Passage says
only a relatively small numberfewer than one hundred species
lead tobring
illness (G)disease
Why: The contrast is 'fewer than one hundred' (small) bring disease, while 'many thousands' help. 'Disease' = illness (G).
The trap: Destruction (C) appears later in the paragraph as 'mutually destructive', which is about the relationship as a whole, not what a few species cause.
Question 18
Answer: BParagraph 6, last sentence
What is our relationship with microbes based on?
Instead we should realise we have a symbiotic relationship, that can be mutually beneficial or mutually destructive.
Question says → Passage says
we should acceptwe should realise
based on partnership (B)a symbiotic relationship
Why: A symbiotic relationship is one where two living things live closely together and depend on each other. That's a partnership (B), and 'mutually' supports the idea of two sides sharing outcomes.
The trap: Destruction (C) is tempting because the sentence ends with 'mutually destructive'. But the relationship can go either way; what it's based on is the partnership itself.
Question 19
Answer: HParagraph 7, last sentence
What 'poor' thing is upsetting the bacterial balance?
our unhealthy, low-fibre diets are disrupting the bacterial balance
Question says → Passage says
Our poorour unhealthy
nutrition (H)low-fibre diets
upsettingdisrupting
Why: The summary lists three causes in a new order. 'Overuse of antibiotics' is copied, so the other two gaps are diets and hygiene. 'Poor' goes naturally with diet, and the box word for diet is nutrition (H).
The trap: Cleanliness (E) also fits 'our poor ___' grammatically, but 'poor cleanliness' would mean dirt, the opposite of the passage's point. Cleanliness goes in the next gap.
Question 20
Answer: EParagraph 7, last sentence
What do we focus on too much?
Our obsession with hygiene, our overuse of antibiotics
Question says → Passage says
our excessive focus onOur obsession with
cleanliness (E)hygiene
Why: An obsession is an excessive focus, and hygiene means keeping clean. Cleanliness (E).
The trap: Solution (A) and regulations (F) don't link to anything in the paragraph. The only real competitor is nutrition, which you've already used for the diet gap.
YES / NO / NOT GIVEN
Questions 21-26
How to attack this block: Antibacterial products can kill the helpful microbes (YES), and exposing children to a dog's bacteria may help them (NO to 'as few as possible'). The squid study is among the 'less appealing' cases (YES). Microbe-coated walls are only imagined for the future (NO). Whether the book has too many case studies, or how well dengue control has gone, is never judged.
Question 21
Answer: YESParagraph 8, second sentence
Might antibacterial products used at home backfire?
the excessive use of household detergents and antibacterial products actually destroys the microbes that normally keep the more dangerous germs at bay
Question says → Passage says
antibacterial products in the homehousehold detergents and antibacterial products
It is possiblethere are studies indicating
fails to have the desired effectdestroys the microbes that normally keep the more dangerous germs at bay
Why: You use these products to protect yourself from germs, but studies suggest they kill the helpful microbes that keep dangerous germs away. That's failing to do what you want, and 'studies indicating' supports 'it is possible'. YES.
The trap: Some students answer NOT GIVEN because 'desired effect' isn't in the text. You have to work out the purpose of antibacterial products yourself: keeping germs away.
Question 22
Answer: NOParagraph 8, last sentence
Should children meet as few bacteria as possible?
keeping a dog as a pet gives children early exposure to a diverse range of bacteria, which may help protect them against allergies later
Question says → Passage says
come into contact withearly exposure to
as few bacteria as possiblea diverse range of bacteria
Why: The research the writer reports says exposure to many kinds of bacteria may protect children. That's the opposite of keeping exposure low, so NO.
The trap: The word 'may' makes some people choose NOT GIVEN. But the writer clearly presents this as a finding that 'turns accepted norms upside down', and the statement contradicts it.
Question 23
Answer: NOT GIVENParagraph 9, second sentence
Does the writer think the book has too many case studies?
Among the less appealing case studies is one about a fungus that is wiping out entire populations of frogs
Question says → Passage says
Yong's book contains… case studiesAmong the less appealing case studies
Why: The writer says some case studies are unappealing, but she never comments on how many there are or whether any should have been cut. NOT GIVEN.
The trap: 'Less appealing' is criticism, so it's easy to slide into 'too many'. Not liking some of them is not the same as saying there are more than necessary. The writer actually ends up praising the book.
Question 24
Answer: YESParagraph 9, second and third sentences
Might the squid case study not appeal to everyone?
Among the less appealing case studies… Another is about squid that carry luminescent bacteria that protect them against predators.
Question says → Passage says
may have limited appealless appealing
bacteria that prevent squid from being attackedsquid that carry luminescent bacteria that protect them against predators
Why: 'Another' links the squid study back to 'the less appealing case studies'. Less appealing = limited appeal. YES.
The trap: The squid sentence on its own sounds neutral, so you have to notice 'Another is about'. It continues the list that started with 'Among the less appealing'.
Question 25
Answer: NOT GIVENParagraph 9, sixth sentence
Has dengue control worked surprisingly well?
Already, in an attempt to stop mosquitoes spreading dengue fever - a disease that infects 400 million people a year - mosquitoes are being loaded with a bacterium to block the disease.
Question says → Passage says
Efforts to control dengue feverin an attempt to stop mosquitoes spreading dengue fever
Why: The writer says the work is happening ('are being loaded'), but gives no results at all, so there's no judgement on success, surprising or otherwise. NOT GIVEN.
The trap: 'Already' and the 'place of wonder' sentence before it make the project sound successful. 'An attempt' tells you it's in progress, not that it's worked.
Question 26
Answer: NOParagraph 9, last two sentences
Are infection-fighting microbes already inside some hospital walls?
In the future, our ability to manipulate microbes means we could construct buildings with useful microbes built into their walls to fight off infections. Just imagine a neonatal hospital ward
Question says → Passage says
have already been putIn the future… we could construct / Just imagine
inside the wallsbuilt into their walls
reduce the risk of infectionto fight off infections
Why: 'In the future', 'could' and 'Just imagine' all show this hasn't happened yet. The statement says 'already', which contradicts the writer, so it's NO.
The trap: The word 'Already' does appear in the paragraph, but it belongs to the dengue sentence. Many students carry it over to the hospital idea.
H (nutrition). 'Unhealthy, low-fibre diets' becomes 'poor nutrition'. 'Cleanliness' goes in the last gap, for hygiene.
Words from this passage worth keeping
ubiquitous(Paragraph 1)
found everywhere
at our peril(Paragraph 1)
at great risk to ourselves
adept(Paragraph 4)
very skilled
a knack of(Paragraph 4)
a natural ability to do something well
teeming with(Paragraph 5)
full of large numbers of moving things
symbiotic(Paragraph 6)
describing a close relationship where each side depends on the other
unravelling(Paragraph 7)
gradually working out something complicated
keep at bay(Paragraph 8)
stop something dangerous from coming near
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The full Cambridge 16 Test 2 reading paper: all three passages, 60 minutes, marked the second you finish with a review of every answer. Already done it? Take it again and see if the same traps still get you.
Cambridge IELTS 16, Test 2, Reading Passage 2. The passage and questions belong to Cambridge University Press and are not reproduced here. We quote short extracts only as evidence for our own commentary, and the answers are published for self-marking. Get the book for the full text, or sit the test on Langujet.
