The Workbook is basically the same as the Student's Book and gives the students a chance to work on their own and so reinforce what they have learned.
The author, Francis A. Andrew, is an English language instructor currently working in the Sultanate of Oman. He has had wide experience in teaching English to a variety of students at all different levels. His experience covers the teaching of general English and English for Specific Purposes. The series Ask A Policeman falls into the latter category.