Is there anybody out there? The Search for Extra-terrestrial Intelligence: reading answers and analysis
An overview of SETI, the search for radio signals from alien civilisations. It covers why we search, the assumptions scientists make about alien life, the odds that life exists elsewhere, how radio searches are run, and why there's no hurry to reply if a signal ever arrives.
The headings (14-17) cover B to E, one each. The short answers (18-20) jump around: A, the introduction, then D. The YES / NO / NOT GIVEN statements (21-26) move in order from A to E.
Answer key and self-check
Type what you wrote and hit mark. Hide the key first if you haven't done the passage yet. Every question number jumps to its explanation.
How to attack this block: Several headings fit a single detail, especially the one about distances, which pops up in C, D and E. Ask what the whole paragraph is doing: setting rules, estimating odds, describing searches, or deciding how to respond.
Question 14
Answer: ivParagraph B, first sentence
Which heading sums up paragraph B?
In discussing whether we are alone, most SETI scientists adopt two ground rules.
Question says → Passage says
Assumptions underlying the searchtwo ground rules / we make a very conservative assumption
Why: B sets out the two starting rules SETI scientists work by: ignore UFOs, and assume the life form is roughly like us. Both are assumptions the search is built on, so the answer is iv.
The trap: vi (Knowledge of extra-terrestrial life forms) is tempting because B describes what the aliens might be like, with green heads and carbon chemistry. But that's what scientists assume, not what they know. C is the paragraph about how little we know.
Question 15
Answer: viiParagraph C, middle
Which heading sums up paragraph C?
it seems inconceivable that at least one of these planets does not have a life form on it
Question says → Passage says
Likelihood of lifeinconceivable that at least one of these planets does not have a life form / perhaps one in 100,000 stars might have a life-bearing planet
Why: C weighs up the numbers: billions of stars and galaxies, and a best guess of one life-bearing planet per 100,000 stars. The whole paragraph is building an estimate of how likely life is elsewhere, so vii.
The trap: iii (Vast distances to Earth's closest neighbours) picks up the last sentence about neighbours 100 light years away. That's one detail, and the writer actually says it's 'almost next door', not vast. vi also fits only the opening line.
Question 16
Answer: iParagraph D, second sentence
Which heading sums up paragraph D?
all searches to date have concentrated on looking for radio waves in this frequency range
Question says → Passage says
Seeking the transmission of radio signalslooking for radio waves / search many frequencies at once
Why: D explains why searches use radio waves, then describes the searches themselves: Parkes, the NASA project, Arecibo, Nancy and the Deep Space Network. It's all about looking for radio signals, so i.
The trap: iii can catch you because D mentions 'the vast distances across the galaxy'. That phrase only explains why radio is the best choice; it isn't the topic of the paragraph.
Question 17
Answer: iiParagraph E, first two sentences
Which heading sums up paragraph E?
There is considerable debate over how we should react if we detect a signal from an alien civilisation. Everybody agrees that we should not reply immediately.
Question says → Passage says
Appropriate responses to signalshow we should react if we detect a signal / whether to reply
Why: E is about what to do if a signal arrives: don't reply straight away, think through the ethics, take time drafting a reply. That's the 'appropriate response', so ii.
The trap: E mentions stars 'hundreds of light years away', which points some students to iii. The distance is only there to explain why there's no hurry to reply.
Short answers (NO MORE THAN THREE WORDS AND/OR A NUMBER)
Questions 18-20
How to attack this block: Each answer has a nearby number or phrase that looks right and isn't. Check that your figure is the one the question describes (a planet's lifetime, the targeted search) and not a neighbouring one.
Question 18
Answer: several billion yearsParagraph A, middle
How long can a planet like Earth be expected to last?
Since the lifetime of a planet like ours is several billion years
Question says → Passage says
life expectancy of Earththe lifetime of a planet like ours
Why: 'Life expectancy' is 'lifetime', and 'Earth' is 'a planet like ours'. The answer is 'several billion years', exactly three words.
The trap: 'A few thousand years' is how long we've had civilisation, and 'another two thousand years' is the writer's question about our survival. Neither is the planet's lifetime.
Question 19
Answer: radioIntroduction, first sentence
Also accepted: radio waves / radio signals
What type of signal is SETI looking for?
as we search for radio signals from other intelligent civilisations
Question says → Passage says
SETI scientists are searching forwe search for
signals from other intelligent civilisationssignals from other intelligent civilisations
Why: The question repeats the passage almost word for word, so the gap is the word before 'signals': 'radio'. 'Radio signals' or 'radio waves' are also accepted.
The trap: Some students look only in the lettered paragraphs and miss the introduction. Paragraph D says 'radio waves' too, so you'd still get there, but the first sentence is the direct match.
Question 20
Answer: 1000Paragraph D, near the end
Also accepted: 1000 stars / 1,000
How many stars are the biggest radio telescopes checking?
This part of the project is searching the nearest 1000 likely stars with high sensitivity
Question says → Passage says
the world's most powerful radio telescopesthe world's largest radio telescopes
How many starsthe nearest 1000 likely stars
Why: The targeted search uses the world's largest telescopes, Arecibo and Nancy, and covers the nearest 1000 stars. Write '1000' (or '1,000').
The trap: 'A few hundred stars' is how many have been searched so far with no result. That's a different, earlier figure.
YES / NO / NOT GIVEN
Questions 21-26
How to attack this block: These test the writer's views, so cautious wording still counts as a view. The two NOT GIVENs mention real things from paragraph D (Australian searches, Congress) but add a claim the writer never makes. The two NOs contradict clear statements about detections and replying.
Question 21
Answer: YESParagraph A, last sentence
Does the writer think aliens might help humans deal with big problems?
It is even possible that the older civilisation may pass on the benefits of their experience in dealing with threats to survival such as nuclear war and global pollution
Question says → Passage says
may be able to helpmay pass on the benefits of their experience
overcome serious problemsdealing with threats to survival
Why: The writer says an older civilisation might share what it learned about surviving threats like nuclear war and pollution. That's helping us overcome serious problems, so YES.
The trap: 'It is even possible' sounds very cautious, so some write NOT GIVEN. The statement also says 'may', so the caution matches.
Question 22
Answer: YESParagraph B, middle
Are SETI scientists looking for life that is similar to us?
we make a very conservative assumption that we are looking for a life form that is pretty well like us
Question says → Passage says
resembles humans in many wayspretty well like us / it will nevertheless resemble us
Why: The second ground rule is exactly this: the target life form is 'pretty well like us'. The paragraph then lists the ways it should resemble us.
The trap: 'Two green heads and seven fingers' makes the aliens sound very different. Read on: 'nevertheless resemble us' in how they communicate, live and are built chemically.
Question 23
Answer: NOT GIVENParagraph D, middle
Have America and Australia worked together on research?
So far there have been a number of searches by various groups around the world, including Australian searches using the radio telescope at Parkes
Question says → Passage says
AustraliansAustralian searches
The Americansthe American-operated telescope in Arecibo
Why: Australian searches and an American-run telescope are both mentioned, but separately. Nothing says the two countries worked together.
The trap: Seeing both nationalities in one paragraph makes people link them. Co-operation needs to be stated, and it isn't.
Question 24
Answer: NOParagraph D, middle
Have SETI scientists already received radio signals from several stars?
Until now there have not been any detections from the few hundred stars which have been searched.
Question says → Passage says
So farUntil now
have picked up radio signalsthere have not been any detections
Why: 'Until now' = 'so far', and there have been no detections at all. The statement claims signals from several stars, which the writer directly denies.
The trap: 'A few hundred stars' sounds like 'several stars'. Those stars were searched, but nothing was found.
Question 25
Answer: NOT GIVENParagraph D, middle
Did some members of Congress criticise the NASA project?
The scale of the searches has been increased dramatically since 1992, when the US Congress voted NASA $10 million per year for ten years
Question says → Passage says
The NASA projectvoted NASA $10 million per year
Why: Congress voted the money, and that's all the writer says about Congress. There's no mention of any objection or debate.
The trap: A vote can suggest some people voted against, but that's your inference, not the writer's view. Nothing contradicts it either, so it's NOT GIVEN, not NO.
Question 26
Answer: NOParagraph E, second sentence
Does the writer think we must answer a signal quickly?
Everybody agrees that we should not reply immediately.
Question says → Passage says
respond promptlyreply immediately
it will be importantLuckily, there is no urgency about this
Why: The writer says nobody thinks we should reply immediately and that there is 'no urgency'. Delays of years or decades are 'not important'. That's the opposite of the statement, so NO.
The trap: Some students choose NOT GIVEN because the writer reports what 'everybody' agrees. But the writer clearly shares the view: 'Luckily, there is no urgency'.
C ends with our nearest neighbours being 100 light years away, which pulls people to the 'vast distances' heading. The writer calls that 'almost next door', and the paragraph is really estimating how likely life is.
Congress voted the funding, and that's all. No criticism is mentioned, so NOT GIVEN, not NO.
Words from this passage worth keeping
intermittently(Introduction)
on and off, not continuously
tenuous(A)
weak and easily lost
conservative(B)
cautious, not going beyond what is safe to assume
inconceivable(C)
impossible to imagine or believe
attenuated(D)
made weaker
traversing(D)
travelling across
undirected(D)
not aimed at any particular target
drafts(E)
writes a first version of something
Sit this test on Langujet, then come back
The full Cambridge 9 Test 1 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 9, Test 1, 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.
