The Romans borrowed the Persian qanat method: vertical shafts dug along a line of posts, joined underground, with plumb lines to keep them straight. For high mountains they dug from both ends (counter-excavation), which needed careful surveying and sometimes went wrong, as at Saldae. Tunnels also served roads and gold mines, and hard rock could take decades.
harbourAlso accepted: harbor / the harbour / the harbor
Where the answers sit
The diagram labels (1-6) come from the second and third paragraphs. TRUE / FALSE / NOT GIVEN (7-10) is all in the counter-excavation paragraph. The short answers (11-13) are in the last two paragraphs.
Diagram labelling (ONE WORD ONLY)
Questions 1-6
How to attack this block: The Persian diagram follows the qanat description: what marked the route, where the water ended up, and the shafts' second job besides removing earth. The Roman shaft diagram uses the next paragraph: the cover made of wood or stone, what hung on the plumb line, and what the handholds were for.
Question 1
Answer: postsParagraph 2, second sentence
What was placed over the hill to keep the tunnel on its route?
the qanat method of tunnel construction, which consisted of placing posts over a hill in a straight line, to ensure that the tunnel kept to its route
Question says → Passage says
to direct the tunnellingto ensure that the tunnel kept to its route
Why: The label describes the purpose (directing the tunnel), and the passage says posts were placed in a line for exactly that reason. The diagram shows several, so write the plural: posts.
The trap: 'Shafts' is the next thing mentioned, but the shafts were dug for access and earth removal. They have their own label further down.
Question 2
Answer: canalParagraph 2, fifth sentence
Where did the water flow to before people used it?
it allowed water to flow from the top of a hillside down towards a canal, which supplied water for human use
Question says → Passage says
water runs intoallowed water to flow… down towards
used by local peoplesupplied water for human use
Why: 'Used by local people' matches 'for human use', and the thing that supplied the water was a canal. Singular, one word.
The trap: 'Settlements' appears earlier ('human settlements in dry areas'), but that's where people lived, not what the tunnel's water ran into.
Question 3
Answer: ventilationParagraph 2, fourth sentence
Besides removing earth, what did the vertical shafts provide?
The excavated soil was taken up to the surface using the shafts, which also provided ventilation during the work.
Question says → Passage says
to remove earthThe excavated soil was taken up to the surface
and forwhich also provided
Why: The label gives one job (removing earth) and asks for a second. 'Also provided' introduces it: ventilation, meaning fresh air for the workers.
The trap: 'Soil' or 'surface' sit in the same sentence, but they belong to the first job, which the label has already covered as 'remove earth'.
Question 4
Answer: lidParagraph 3, third sentence
What covered the top of a Roman shaft?
were covered with a wooden or stone lid
Question says → Passage says
made of wood or stonea wooden or stone
Why: The label's 'made of wood or stone' points straight to 'a wooden or stone lid'. The gap is the noun: lid.
The trap: 'Rod' is also at the top of the shaft, but that's what the plumb line hung from, and nothing says it was wood or stone.
Question 5
Answer: weightParagraph 3, fourth sentence
What was attached to the end of the plumb line?
Romans hung a plumb line from a rod placed across the top of each shaft and made sure that the weight at the end of it hung in the center of the shaft
Question says → Passage says
attached to the plumb linethe weight at the end of it
Why: 'At the end of it' means at the end of the plumb line, and the thing there is the weight. It hung in the centre to show that the shaft was vertical.
The trap: 'Rod' is the other object tied to the plumb line, but at the top, across the shaft. On the diagram, the label sits at the bottom of the line.
Question 6
Answer: climbingParagraph 3, third sentence
What were the handholds and footholds for?
The shafts were equipped with handholds and footholds to help those climbing in and out of them
Question says → Passage says
handholds and footholds used forhandholds and footholds to help those
Why: 'Used for' needs a noun or an -ing form, and the passage gives 'climbing'. It's one word, so leave out 'in and out'.
The trap: 'Help' is the word right after 'footholds', but 'used for help' doesn't say what they helped with. The diagram wants the activity.
TRUE / FALSE / NOT GIVEN
Questions 7-10
How to attack this block: The new method was used when the qanat method wasn't practical, so it didn't replace it (FALSE). The Saldae problem is known from an inscription on the tunnel wall, not a book (FALSE). The two teams did miss each other (TRUE). The passage says the method needed advanced knowledge, but never says who was hired.
Question 7
Answer: FALSEParagraph 4, first two sentences
Did counter-excavation fully replace the qanat method in the 6th century BCE?
a second method of tunnel construction appeared called the counter-excavation method… It was used to cut through high mountains when the qanat method was not a practical alternative.
completely replaced the qanat methodwhen the qanat method was not a practical alternative
Why: The new method was used only in certain cases, when the qanat method wasn't practical. So the qanat method was still in use, and paragraph 6 compares the two as working alternatives. That contradicts 'completely replaced', so FALSE.
The trap: 'A second method… appeared' sounds like a takeover. 'Second' means an extra option, not a replacement.
Question 8
Answer: NOT GIVENParagraph 4, third sentence
Were only experienced builders hired for counter-excavation?
This method required greater planning and advanced knowledge of surveying, mathematics and geometry
Question says → Passage says
a tunnel using the counter-excavation methodThis method
Why: The passage says the method needed advanced knowledge, but it never says who was employed or how experienced they were. NOT GIVEN.
The trap: 'Advanced knowledge' makes it feel obvious that only experts were hired. The method needing knowledge doesn't tell you anything about who was actually employed, and 'only' is a strong claim with no support.
Question 9
Answer: FALSEParagraph 4, last sentence
Was the Saldae problem described in an old book?
An inscription written on the side of a 428-meter tunnel, built by the Romans as part of the Saldae aqueduct system in modern-day Algeria, describes how the two teams of builders missed each other
Question says → Passage says
The information about a problemdescribes how the two teams of builders missed each other
was found in an ancient bookAn inscription written on the side of a 428-meter tunnel
Why: The record of the mistake is an inscription on the tunnel wall itself, not a book. The source is different, so FALSE.
The trap: Some students choose NOT GIVEN, thinking a book might also exist. The passage names the source directly, and it isn't a book, so the statement contradicts it.
Question 10
Answer: TRUEParagraph 4, last sentence
Was the Saldae mistake that the two halves of the tunnel didn't meet?
describes how the two teams of builders missed each other in the mountain and how the later construction of a lateral link between both corridors corrected the initial error
Question says → Passage says
the two parts of the tunnelboth corridors
failed to meetmissed each other in the mountain
The mistakethe initial error
Why: The two teams, digging from each end, 'missed each other', so their tunnels didn't join. A side link had to be built to fix it. TRUE.
The trap: Because the error was later corrected, some people think the tunnel parts did meet in the end. The statement is about the original mistake, and that was the failure to meet.
Short answers (NO MORE THAN TWO WORDS)
Questions 11-13
How to attack this block: Each question names a place, so scan for Dolaucothi, 'inscriptions' and Cevlik. The key accepts short and long forms (architect or the architect's name, harbour or harbor).
Question 11
Answer: goldParagraph 5, sixth sentence
What mineral were the Dolaucothi mines dug for?
Traces of such tunnels used to mine gold can still be found at the Dolaucothi mines in Wales.
Question says → Passage says
built to extractused to mine
Why: Scan for the name Dolaucothi: the same sentence says the tunnels were used to mine gold. One word is enough.
The trap: 'Mineral vein' appears just before, but that's the general term. The question wants the type of mineral.
Question 12
Answer: architectParagraph 6, near the end
Also accepted: the architect / architect's name / the architect's name
Whose name, besides the patron's, might be on a tunnel?
Most tunnels had inscriptions showing the names of patrons who ordered construction and sometimes the name of the architect.
Question says → Passage says
might be carved onto a tunnelhad inscriptions showing… sometimes
In addition to the patronthe names of patrons… and
Why: 'Might' matches 'sometimes', and the second name is the architect's. The key accepts several forms, but 'architect' or 'the architect' is the safest way to stay within the two-word limit.
The trap: 'Builders' and 'workers' appear in the passage, but their names are never said to be carved on tunnels.
Question 13
Answer: harbourParagraph 6, last sentence
Also accepted: harbor / the harbour / the harbor
Which part of Seleuceia Pieria did the Cevlik tunnel protect?
the 1.4-kilometer Cevlik tunnel in Turkey, built to divert the floodwater threatening the harbor of the ancient city of Seleuceia Pieria
Question says → Passage says
built to protectbuilt to divert the floodwater threatening
Why: The floodwater was 'threatening the harbor', and the tunnel moved it away, so the harbour was what it protected. British or American spelling is accepted.
The trap: 'Floodwater' is what the tunnel dealt with, not what it protected. 'City' is too broad: the question already names the city and asks which part of it.
The shafts removed earth and also provided ventilation during the work. The label already mentions removing earth, so the gap is the second job.
Words from this passage worth keeping
adopted(Paragraph 1)
took and started using something from others
at regular intervals(Paragraph 2)
with the same distance between each one
ventilation(Paragraph 2)
the supply of fresh air
plumb line(Paragraph 3)
a string with a weight on the end, used to check that something is vertical
deviated(Paragraph 4)
moved away from the planned direction
lateral(Paragraph 4)
going sideways
vein(Paragraph 5)
a thin layer of mineral running through rock
divert(Paragraph 6)
make something go in a different direction
Sit this test on Langujet, then come back
The full Cambridge 16 Test 4 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 4, Reading Passage 1. 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.
