The key answer of exercise 4
The key to exercise solutions in chapter CLIL 1 for the textbook Wider World 4 - Student's Book with authors Suzanne Gaynor, Kathryn Alevizos and Carolyn Barraclough from Pearson Education
Question
Read the second paragraph again and look at the diagram. Work in pairs. Student A, close your book and describe the process of fracking to your partner. Student B, check your partner's description. Help and correct him / her where necessary.
Answer
Big machines drill a well under the water table and the rocks below it down to a depth of about a kilometre or more. The drilling then goes horizontally for thousands of metres. By forcing water, sand and chemicals into the rock at high pressure, small cracks appear in the rock and shale gas comes out.