Self Study Task GRAMMAR

As a part of my self study today I've revised ,Active and passive questions " source of data AN INTRODUCTION TO ENGLISH GRAMMAR Sidney Greenbaum and Gerald Nelson"few examples of my work , where Active questions had been turned to passiveAc. 1) A team of detectives is investigation the crime.pas. 2) The crime is being investigated by a team of detectives.act.3)The new management has offered employees a better deal.pas.4) Employees have been offered a better deal by the new management.