Read the following passage.
A. Fibre-optic cables carry information as extremely fast flashes of light through thin threads of glass, from lasers at one end to receptors at the other. These glass threads now carry almost all of the world's telephone and data traffic, including the Internet, so text, music, images and video can cross the globe in a split second. Unlike copper cables, glass fibre is not sensitive to lightning, and unlike radio it is not affected by bad weather. By 2009, the world's network of optical fibre was estimated at over 1 billion km.
B. The method depends on how light behaves in glass. A ray of light sent into a fibre bounces off the glass wall and keeps moving forward, because glass has a higher refractive index than the air around it. The core that carries the light is typically about 10 micrometres across, less than a single hair. In the 1960s, light signals could travel only about 20 metres through the fibres then available. In 1966, Charles Kao showed that the main problem was the glass itself, which had to be purified, and the first ultrapure fibre was made in 1970. Kao later shared the 2009 Nobel Prize in Physics.
C. Fibre also links the continents across the ocean floor. The first transatlantic cable, laid in 1956, could carry 36 phone calls at once, and the first optical cable crossed the Atlantic in 1988. By early 2026, TeleGeography estimated that over 1.5 million kilometres of submarine cable were in service. For most of its route a cable is about as wide as a garden hose. Near the shore it is buried under the seabed, but in the deep sea it lies directly on the bottom. There are roughly 200 faults a year, and two thirds are caused by accidents such as fishing vessels and ships dragging anchors.
D. A call from a mobile phone travels wirelessly only as far as the nearest cell tower, and from there it moves through fibre-optic cables on land and under the sea. Content providers such as Google, Meta, Microsoft and Amazon are now major investors in new undersea cables. Satellites still reach areas that are not yet wired, but cables carry far more data at a fraction of the cost. In Canada, the $3.225 billion Universal Broadband Fund pays for high-speed Internet projects in rural and remote communities. The federal government reports that more than 90 per cent of Canadian households are now connected, and it aims to connect every Canadian by 2030.
E. Not given in any of the above paragraphs.
Decide which paragraph, A to D, has the information given in each statement below. Select E if the information is not given in any of the paragraphs.
AI explanationShows the answer. Tap to open.
Correct Answer: D
Why this is correct: Look at Paragraph D. Google, Meta, Microsoft and Amazon are now major investors in new undersea cables. An investor puts money into something.
Passage Reference: Content providers such as Google, Meta, Microsoft and Amazon are now major investors in new undersea cables.
Tips: Find the two company names. Then check what role the text gives them in the new cables.
Why the other options are wrong:
- A: Paragraph A explains what fibre-optic cables carry. It does not name anyone who pays for them.
- B: Paragraph B names Charles Kao, a scientist. It does not name any business that pays for cables.
- C: Paragraph C names TeleGeography, which counted the cable in service. It does not say TeleGeography pays for cables.
- E: Paragraph D names Google and Amazon as investors, so the text covers this.
Correct Answer: B
Passage Reference: In 1966, Charles Kao showed that the main problem was the glass itself, which had to be purified, and the first ultrapure fibre was made in 1970.
Why this is correct: Paragraph B has what you need. In 1966, Charles Kao showed that the main problem was the glass itself. It had to be purified, which means made purer.
Tips: Ask which person made a discovery about the glass. Was it about making the glass purer?
Why the other options are wrong:
- A: Paragraph A describes glass threads and lasers. It names no researcher and no problem with the glass.
- C: Paragraph C tells the history of ocean cables from 1956. It does not discuss how pure the glass is.
- D: Paragraph D is about who pays for cables and who is connected today. No scientist appears.
- E: Charles Kao's finding sits in Paragraph B, so this one is supported.
Correct Answer: C
Passage Reference: There are roughly 200 faults a year, and two thirds are caused by accidents such as fishing vessels and ships dragging anchors.
Why this is correct: Look at Paragraph C. There are about 200 faults a year. Two thirds come from accidents such as fishing vessels and ships dragging anchors. Two thirds is most of them.
Tips: Here you need to know what harms ocean cables most often. Are boats and ships to blame for most of it?
Why the other options are wrong:
- A: Paragraph A says glass fibre is not harmed by lightning. Boats and ships are not mentioned.
- B: Paragraph B describes how early glass could carry light only a short way. That is a different kind of problem.
- D: Paragraph D compares cables with satellites for data and cost. It does not talk about damage.
- E: Paragraph C counts the faults and gives their causes, so the text answers this.
Correct Answer: D
Passage Reference: A call from a mobile phone travels wirelessly only as far as the nearest cell tower, and from there it moves through fibre-optic cables on land and under the sea.
Why this is correct: Paragraph D follows a call from a mobile phone. It goes wirelessly only as far as the nearest cell tower. After that, it moves through fibre-optic cables.
Tips: Three paragraphs mention phones. Find the call that goes through the air first.
Why the other options are wrong:
- A: Paragraph A mentions telephone traffic in general. It does not follow a call from a mobile phone.
- B: Paragraph B explains how light moves inside a fibre, not how a phone call gets there.
- C: Paragraph C mentions 36 phone calls on the 1956 cable. Nothing is said about a mobile phone.
- E: Paragraph D describes the path of a mobile call, so the reading supports this.
Correct Answer: B
Passage Reference: In the 1960s, light signals could travel only about 20 metres through the fibres then available.
Why this is correct: Go to Paragraph B. In the 1960s, light could travel only about 20 metres through the fibres of that time. Twenty metres is a very short distance.
Tips: Think about the early days of fibre. Check how far light could go through it back then.
Why the other options are wrong:
- A: Paragraph A gives a huge length, over 1 billion km of fibre. That is the size of the network, not how far light went early on.
- C: Paragraph C gives the total length of ocean cables in service by 2026. It says nothing about how far light went in early fibres.
- D: Paragraph D describes how fibre is used now. It gives no distances for light signals.
- E: Paragraph B gives the 20 metre limit, so the text does say this.
Correct Answer: E
Passage Reference: In Canada, the $3.225 billion Universal Broadband Fund pays for high-speed Internet projects in rural and remote communities.
Why this is correct: The Universal Broadband Fund appears in Paragraph D, which says it pays for high-speed Internet projects in rural and remote places. It never says where the fund's money comes from. Telephone companies are not mentioned.
Tips: Paying for projects and paying into the fund are different ideas. Look for who supplies the money.
Why the other options are wrong:
- A: Paragraph A explains how light carries data through glass. No fund is mentioned.
- B: Paragraph B tells the history of purer glass fibre. Money for Internet projects is not part of it.
- C: Paragraph C describes cables under the sea and what damages them. It says nothing about a fund.
- D: Paragraph D names the fund and what it pays for. It does not say who puts money into it.
Correct Answer: C
Passage Reference: Near the shore it is buried under the seabed, but in the deep sea it lies directly on the bottom.
Why this is correct: Look at Paragraph C. Near the shore, a cable is buried under the seabed. In the deep sea it lies on the bottom. The shore is the coast, and the seabed is the sea floor.
Tips: Focus on where cables sit close to the coast. Do they rest on top of the sea floor or beneath it?
Why the other options are wrong:
- A: Paragraph A explains what the cables carry. It does not say where they lie.
- B: Paragraph B describes the inside of a fibre, such as its core. It does not say where cables are laid.
- D: Paragraph D says fibre runs on land and under the sea. It does not say where cables are buried.
- E: Paragraph C explains what happens near the shore, so this is supported.
Correct Answer: B
Passage Reference: A ray of light sent into a fibre bounces off the glass wall and keeps moving forward, because glass has a higher refractive index than the air around it.
Why this is correct: In Paragraph B, a ray of light bounces off the glass wall and keeps moving forward. Bouncing off a wall is reflecting.
Tips: Paragraph A sends the light in. Look for what the light does inside the glass.
Why the other options are wrong:
- A: Paragraph A says lasers send the light out. It does not explain what keeps the light inside the glass.
- C: Paragraph C gives the outside size of a cable, about as wide as a garden hose. It says nothing about light inside.
- D: Paragraph D is about how people use fibre today. It does not explain the science.
- E: Paragraph B describes the light bouncing off the wall, so the text answers this.
Correct Answer: A
Passage Reference: Unlike copper cables, glass fibre is not sensitive to lightning, and unlike radio it is not affected by bad weather.
Why this is correct: Look at Paragraph A. Unlike radio, glass fibre is not affected by bad weather. Storms are bad weather, so they do not disturb fibre.
Tips: Find where fibre is compared with radio. Check what kind of trouble fibre avoids.
Why the other options are wrong:
- B: Paragraph B explains how light travels in glass. It does not compare fibre with radio.
- C: Paragraph C lists causes of faults in ocean cables, such as anchors. Weather is not one of them.
- D: Paragraph D compares cables with satellites, not with radio. It does not mention weather.
- E: Paragraph A compares fibre with radio in bad weather, so the text covers this.
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