6 As soon as the fire ..... (put out) the fire fighters left.

Passive voice explanation:

• The passive voice is used to show what happens to the subject.
• It is formed with the verb 'to be' (in the correct tense) + the past participle of the main verb.
• When describing completed actions in the past, we use 'was/were' + past participle.
• The phrase 'as soon as' indicates that one action happened immediately after another.

Answer:

6 As soon as the fire was put out, the fire fighters left.