Reading › Re-order Paragraphs
Exercise 7
Task reminder: Type the correct order (A, B, C…) in the boxes to restore the original paragraph sequence. Start by finding the topic sentence — it has no backward references.
1. Black Holes
| A. At the centre of a black hole is a singularity — a point of infinite density where the known laws of physics break down. | |
| B. When a sufficiently massive star exhausts its nuclear fuel, gravity causes it to collapse catastrophically inward. | |
| C. The result is a region of spacetime with gravitational pull so extreme that nothing — not even light — can escape once it crosses the event horizon. | |
| D. Scientists detect black holes indirectly through their gravitational effects on nearby stars and gas, and through the gravitational waves produced when two black holes merge. |
Show Answer 2. The Concept of Gross Domestic Product Show Answer 3. Plate Tectonics Show Answer A. Critics argue that GDP fails to capture many dimensions of human welfare — it counts pollution clean-up as economic output, ignores unpaid labour such as childcare, and says nothing about income distribution. B. GDP — Gross Domestic Product — is the total monetary value of all goods and services produced within a country in a given period, typically one year. C. These limitations have prompted economists and policymakers to develop alternative or supplementary measures, including the Human Development Index and national wellbeing surveys. D. It became the dominant measure of economic performance after World War II, used by governments, businesses, and international organisations to compare economies and track growth. A. Evidence for the theory accumulated through the twentieth century, including the matching geological formations and fossil records found on opposite sides of the Atlantic Ocean. B. The theory of plate tectonics, developed in the 1960s, holds that Earth’s outer shell is divided into several large plates that move slowly across the mantle. C. The boundaries between plates are geologically active zones: where plates collide, mountain ranges form or one plate is subducted beneath another; where they separate, new ocean floor is created. D. Earthquakes and volcanic eruptions occur predominantly along these boundaries, making plate tectonics fundamental to understanding and predicting geological hazards.