Cover of the textbook Spark 4 - Student's Book

The key answer of exercise 6

A: Fred got promoted again. B: Wow! He must be very good at his job.
A: Isn't that the new chef? B: It can't be. He looks too young to be a chef.
A: I've been calling, but there's no answer. B: Oh, they may be closed for lunch.
A: Greg isn't in his office. B: He must be at a meeting.
A: His house is near the train station. B: It can't be quiet.

The key to exercise solutions in chapter 7b - Grammar for the textbook Spark 4 - Student's Book with authors Virginia Evans, Jenny Dooley from Express Publishing

Chapter

Exercise