The key answer of exercise 4
The key to exercise solutions in chapter 8.5 - Grammar for the textbook Focus 3 - Student's Book with authors Daniel Brayshaw, Vaughan Jones, Bartosz Michałowski and Sue Kay from Pearson Education
Question
Read the GRAMMAR FOCUS. Did Judy and Mike make the changes to their house or did they arrange for somebody else to do it?
Answer
Someone else did it for them.