IELTS Reading Passages - Practice Test 4

The Liquid-Propellant Rocket and Alternatives

• Liquid-Propellant Rocket:

  • Uses liquid propellants for power.
  • High density of liquids allows for smaller propellant tanks.
  • Lightweight pumps can move liquid propellant from tanks to the engine at low pressure.
  • Smaller tanks and lighter pumps effectively lower the rocket's mass ratio.

• Bipropellant Rockets:

  • Common type of liquid-propellant rocket.
  • Two tanks: one with liquid fuel, the other with a liquid oxidizer (e.g., liquid hydrogen or hydrocarbon fuel, liquid oxygen combination).
  • Pumps connect tanks to the combustion chamber.
  • Fuel and oxidizer react and combust in the chamber.
  • Spent fuel is expelled through the nozzle, creating thrust for takeoff.

• Advantages of Liquid-Propellant Rockets:

  • Higher energy content for more thrust.
  • Tankage efficiency: liquid propellant has a density similar to water and requires modest pressure to prevent vaporization, allowing for lightweight tanks.
  • Gasses are less dense and require more pressure for storage, resulting in heavier tankage and a higher rocket mass ratio.
  • Reusable for multiple flights (e.g., Space Shuttle program).
  • Can be shut down and reignited multiple times.

• Issues with Liquid-Propellant Rockets:

  • Slosh: Movement of liquid inside the rocket can lead to loss of control and confuse computerized guidance systems.
  • Functional complexity: High-speed moving parts operating at high temperatures increase the probability of failures.
  • Turbopumps are difficult to design and prone to failures like overspeeding or shedding when operated at high speed.
  • Require fine-tuning and operate with a small margin for error, leading to high maintenance in build, design, storage, and flight logistics.

• Solid-Fuel Rockets:

  • Advantage: Long storage life; can be stored indefinitely and readied for operation quickly.
  • Less volatile and easier to transport, making them suitable for military use.

• NASA's Use of Rockets:

  • Uses solid-fuel rockets for initial thrust during space shuttle launches.
  • Relies on liquid-propellant rockets in later stages for longer thrust duration.

• Hybrid Rocket Models:

  • Combine aspects of solid and liquid rockets.
  • Mechanically and functionally simpler, requiring only one liquid tank.
  • Safer as they can be loaded onsite and transported in a benign state.
  • Being researched by space science agencies.

Education Cuts Counterproductive to Long-Term Goals

• University Rankings:

  • Irish universities performed poorly in global rankings.
  • Trinity College Dublin fell from 52nd to 65th.
  • University College Dublin dropped to 134th.
  • University College Cork rose slightly from 184th to 181st.

• Reasons for Slippage:

  • University presidents blame government cutbacks in third-level education.
  • Claim this undermines Ireland's reputation and damages economic recovery prospects.

• Comparison with UK and US Universities:

  • UK universities charge undergraduates an average of $€10,000$ per annum.
  • University education in America is even more expensive.
  • Third-level education in Ireland is still free, but there are calls for fees to be reintroduced.

• Attracting Foreign Students:

  • Seen as crucial for the future due to funding cuts.
  • Poor performance in rankings makes it harder to attract foreign fee-paying students.
  • Without funding from foreign students, Irish universities will continue to decline in rankings; it's a vicious circle.

• Government Policy vs. Funding Cuts:

  • Government aims to attract double the number of foreign students by 2018.
  • Each international student spends an average of $€20,000$ in fees and expenses.
  • Doubling the number of foreign students would significantly boost the economy and university funding.

• Long-Term Benefits of Foreign Students:

  • Well-educated and skilled international students could open up new trading and investment opportunities in their native countries.
  • Government's decision to divert funding is short-sighted and counterproductive.

• Reintroduction of University Fees:

  • Met with anger from parent and student groups.
  • Students' Association of Ireland threatened a protest march.

• Arguments Against Fees:

  • Ireland is not a classist society, and everyone should have equal opportunity to attend third-level courses.
  • Reintroducing fees would make university the preserve of an elite few, or burden students with huge debts.
  • Ireland's system is not elitist unlike UK's which burdens students with debt.

Is Paradise Forever Lost?

• Paragraph A: Backpackers no longer breaking new ground

  • Traveling on a shoestring has become too common.
  • Lower travel costs have diminished the hardships once endured by budget travelers.
  • This has reduced the enjoyment of "roughing it" in search of unique experiences.
  • Globe-trotting has become less attractive due to overcrowding and artificial experiences.
  • People sought to escape the masses, not join them.

• Paragraph B: Reality bites for peace-seeking traveler

  • Rex, 25, dropped out of Engineering at Oxford to travel the world.
  • He was disillusioned with life in London and wanted to branch out.
  • His parents supported his decision.
  • Rex's passion for the journey waned as he encountered many foreigners like himself.
  • The experience of local culture felt artificial.

• Paragraph C: The mood is lifted at last

  • Rex almost gave up on finding an authentic experience.
  • He decided to stop over in Greece on his way back to London.
  • He found himself in Corfu on a beautiful spring day in March with few tourists.
  • His spirits lifted as he dined in the old town at a small, family-owned taverna.
  • The owner introduced him to his family and chatted with him.

• Paragraph D: Paradise found at last but disturbed by new arrivals

  • The taverna owner told Rex about Kefalonia, where he grew up.
  • Rex stayed with the owner's brother, Nikos, who showed him around the island.
  • Rex spent two months with Nikos's family, exploring land, sea, caves, rivers, waterfalls, lakes, forests, and mountains.
  • The experience felt real, including swimming with turtles with Nikos' daughter Eliza.
  • One evening, a busload of tourists arrived, disrupting the tranquility.
  • Rex retreated back to London, realizing that paradise can be found even in commercialized destinations if you know when and where to look.

• Paragraph E: Never give up on finding what you're looking for

  • Rex's story reminds people to keep searching for what they are looking for.
  • Rex found his paradise in Greece, known for package-holiday goers.
  • For most of the year, Greece transforms into something magical, especially a quiet island gem on the Ionian Sea.
  • Keep searching!