The passive for focus

We use the passive when we wish to focus on a happening which is more important to us than who or what causes the happening - or

12 The passive and the causative

when there is simply no need to mention the doer. If we say:

Our roof was damaged in last night s storm we are mainly concerned with the roof and what happened to it. Similarly:

My cars been scratched' Thousands of'beaches are polluted The happening may concern people:

Charles I was beheaded in 1649