Cover of the textbook Cutting Edge Upper-Intermediate - Student's Book

The key answer of exercise 2

Pictured top left: 'stirring up the oceans' - relates to climate change. Long plastic tubes would stir up the sea, bring up cold water to the surface, absorb heat and CO, and cool the planet.
Pictured top right: building a giant umbrella in space' - relates to asteroid strikes. The umbrella would collect solar energy and refocus it on the asteroid, deflecting it away from the earth.
Pictured bottom left: pumping toxic chemicals into the atmosphere' relates to climate change. A 12-mile pipe would pump toxic chemicals into the atmosphere to form a protective layer, reflecting sunlight and cooling the earth.
Pictured bottom right: building a huge nuclear bomb' relates to asteroid strikes. A nuclear bomb would be launched to destroy an approaching asteroid.

The key to exercise solutions in chapter 11 - Reading for the textbook Cutting Edge Upper-Intermediate - Student's Book with authors Sarah Cunningham, Peter Moor and Jonathan Bygrave from Pearson Education

Chapter

Exercise