The history of watching Venus cross the Sun. Halley saw that timing a transit from distant places could give the Earth-Sun distance, expeditions set out to do it, and Le Gentil's attempts went badly wrong. Optical effects spoiled the timings, but Encke still produced a good figure, and the parallax method now reaches the stars.
The paragraph matching (14-17) uses the later paragraphs, D to G, out of order. The people (18-21) appear in B, C, D and F. The TRUE / FALSE / NOT GIVEN statements (22-26) follow the passage from B to F.
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.
Q
Your answer
Answer
Questions 14-17 · Matching information (paragraphs A-G)
How to attack this block: The items describe kinds of content: examples of uses, an event that stopped an observation, a look to the future, physical effects. Paragraph E's timing problems and D's failed observation are easy to mix up, so check whether the transit was actually seen.
Question 14
Answer: FParagraph F
Which paragraph shows the parallax idea being used in more than one way?
finally determined a value for the AU based on all these parallax measurements… The parallax principle can be extended to measure the distances to the stars.
Question says → Passage says
different ways in which the parallax principle has been appliedbased on all these parallax measurements / can be extended to measure the distances to the stars
Why: F gives two uses: Encke's value for the Earth-Sun distance from transit parallax, and measuring the distance to stars from Earth's orbit. Two applications means 'examples of different ways'.
The trap: B explains what parallax is and how Halley planned to use it. That's one planned use, not several applied examples.
Question 15
Answer: DParagraph D, last sentence
Which paragraph describes something that stopped someone observing a transit?
Ironically after travelling nearly 50,000 kilometres, his view was clouded out at the last moment
Question says → Passage says
an event which prevented a transit observationhis view was clouded out / the British were besieging his observation site
Why: Le Gentil's story in D has two blocking events: a British siege of his site and clouds at the second transit. Either way, D describes what prevented his observation.
The trap: E describes problems with timing (the black drop and the halo), but astronomers still observed the transits. Those effects spoiled accuracy, they didn't prevent observation.
Question 16
Answer: GParagraph G, last sentence
Which paragraph looks ahead to discoveries that transits made possible?
such transits have paved the way for what might prove to be one of the most vital breakthroughs in the cosmos
Question says → Passage says
leading on from transit observationssuch transits have paved the way for
potential future discoverieswhat might prove to be one of the most vital breakthroughs / detecting Earth-sized planets orbiting other stars
Why: 'Paved the way for' means 'led on to', and 'might prove to be' marks a possible future breakthrough: finding Earth-sized planets around other stars.
The trap: F's final lines about measuring star distances can feel forward-looking, but that's something astronomers already do.
Question 17
Answer: EParagraph E
Which paragraph describes features of Venus that early instruments couldn't get around?
Venus exhibits a halo of light when it is seen just outside the Sun's disc… both effects made it impossible to obtain accurate timings.
Question says → Passage says
physical states connected with Venusthe 'black drop' effect / a halo of light / surrounded by a thick layer of gases
early astronomical instruments failed to overcomeas precise as instruments would allow / made it impossible to obtain accurate timings
Why: E names two effects tied to Venus itself, the black drop and the halo caused by its gases. The instruments of the day were as precise as they could be, but these effects still made accurate timing impossible.
The trap: D also describes a failed measurement (the ship's rolling), but that's a problem with the ship, not with Venus.
Matching statements to people
Questions 18-21
How to attack this block: Separate idea from result. Halley worked out the method, Encke produced the figure, Kepler linked distance and orbital speed, and Le Gentil saw a transit but couldn't measure it.
Question 18
Answer: DParagraph F, first two sentences
Who worked out the Earth-Sun distance from Venus observations quite accurately?
Johann Franz Encke, Director of the Berlin Observatory, finally determined a value for the AU based on all these parallax measurements: 153,340,000 km. Reasonably accurate for the time
Question says → Passage says
calculated the distance of the Sun from the Earthdetermined a value for the AU
with a fair degree of accuracyReasonably accurate for the time
Why: The AU is the Earth-Sun distance (defined in B), and Encke 'determined a value' for it that was 'reasonably accurate'. He is D.
The trap: Halley worked out that the distance could be measured 'to 1 part in 500', which sounds like a calculation. He described a method; he never produced the figure.
Question 19
Answer: AParagraph B, middle
Who saw that comparing transit observations could give the Earth-Sun distance?
By timing the transit from two widely-separated locations, teams of astronomers could calculate the parallax angle… Calculating this angle would allow astronomers to measure what was then the ultimate goal: the distance of the Earth from the Sun.
Question says → Passage says
He understoodHe realised
comparing observations of a transittiming the transit from two widely-separated locations
Why: Halley realised that timing a transit from two distant places gives the parallax angle, and that angle gives the Earth-Sun distance. That's the idea in the statement: A.
The trap: Encke actually did the calculation (Q18). The statement is about understanding that it could be done, which was Halley.
Question 20
Answer: BParagraph C, second sentence
Who realised a planet's orbit time depends on how far it is from the Sun?
Johannes Kepler, in the early 17th century, had shown that the distances of the planets from the Sun governed their orbital speeds
Question says → Passage says
depends ongoverned
the time taken by a planet to go round the Suntheir orbital speeds
Why: 'Governed' means 'controlled', so speed depends on distance. A planet's orbital speed decides how long it takes to go round. That's Kepler, B.
The trap: Halley is the main figure in C, so people pick him by default. The sentence about distances and speeds is credited to Kepler.
Question 21
Answer: CParagraph D, middle
Who saw a Venus transit but couldn't make any measurements?
Le Gentil saw a wonderful transit - but the ship's pitching and rolling ruled out any attempt at making accurate observations.
Question says → Passage says
He witnessed a Venus transitsaw a wonderful transit
was unable to make any calculationsruled out any attempt at making accurate observations
Why: On the warship Le Gentil saw the first of the pair of transits, but the moving ship made measurement impossible. That's C.
The trap: Halley saw a transit too, but it was of Mercury, and he made use of it. The statement needs a Venus transit.
TRUE / FALSE / NOT GIVEN
Questions 22-26
How to attack this block: The two FALSEs are about what Halley and Le Gentil actually saw, so check which planet and which transit. The NOT GIVEN adds a detail (toxic) to something the passage does mention (a thick layer of gases).
Question 22
Answer: FALSEParagraphs B and C
Did Halley see one transit of Venus?
Halley observed a transit of the innermost planet, Mercury… he accurately predicted that Venus would cross the face of the Sun in both 1761 and 1769 - though he didn't survive to see either.
Question says → Passage says
observed one transitobserved a transit of the innermost planet, Mercury
of the planet Venusdidn't survive to see either
Why: The transit Halley watched was of Mercury. He predicted the two Venus transits but died before either happened, so he saw no Venus transit at all.
The trap: 'Halley observed a transit' is in B, and only the planet's name is different. Check which planet before you write TRUE.
Question 23
Answer: FALSEParagraph D, last sentence
Did Le Gentil manage to see the second transit?
before setting off to observe the next transit in the Philippines. Ironically after travelling nearly 50,000 kilometres, his view was clouded out at the last moment
Question says → Passage says
a second Venus transitthe next transit
managed to observehis view was clouded out
Why: He went to the Philippines for the next transit, but clouds blocked his view at the last moment. He did not observe it.
The trap: He did see the first one, from the ship, so 'observe' feels half right. The statement is about the second, which he missed.
Question 24
Answer: TRUEParagraph E, second sentence
Does Venus look out of shape when it starts crossing the Sun?
When Venus begins to cross the Sun's disc, it looks smeared not circular
Question says → Passage says
starts to pass in front of the Sunbegins to cross the Sun's disc
appears distortedlooks smeared not circular
Why: 'Starts to pass in front of' is 'begins to cross', and 'smeared not circular' means the shape looks distorted. A direct match.
The trap: The halo appears when Venus is 'just outside' the disc, so don't mix it up with this effect. The smeared shape is the black drop.
Question 25
Answer: NOT GIVENParagraph E, last sentence
Did early astronomers think Venus's atmosphere was poisonous?
this showed astronomers that Venus was surrounded by a thick layer of gases refracting sunlight around it
Question says → Passage says
the atmosphere on Venusa thick layer of gases
Why: The halo told astronomers that Venus had a thick layer of gases. What those gases were, and whether they were toxic, is never mentioned.
The trap: Knowing Venus has a harsh atmosphere in real life pushes people to TRUE. Answer from the passage only: it says 'thick', not 'toxic'.
Question 26
Answer: TRUEParagraph F, second half
Can the parallax principle be used to find how far away the stars are?
The parallax principle can be extended to measure the distances to the stars.
Question says → Passage says
allows astronomers to work outcan be extended to measure / lets astronomers calculate the distance
how far away distant stars arethe distances to the stars
Why: The sentence says it directly, and the lines after explain how: compare a star's position six months apart and use the width of Earth's orbit.
The trap: Radar is said to have 'superseded' transits, which can make you think parallax is no longer used. Radar replaced transits for the AU; parallax still works for stars.
E's black drop and halo spoil the timings, but the transits were still observed. Only D has an event that stopped an observation.
Words from this passage worth keeping
polymath(B)
a person who knows a lot about many subjects
desolate(B)
empty and bleak
pin down(D)
establish something exactly
thwarted(D)
stopped from doing what you planned
undaunted(D)
not discouraged by difficulty
dogged by(E)
constantly troubled by
superseded(F)
replaced by something better
paved the way for(G)
made something possible later
Sit this test on Langujet, then come back
The full Cambridge 9 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 9, 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.
