Answer:
The revised version of the sentence would be as follows: When we searched the school for damage, we discovered a broken window.
Explanation:
In most English sentences with an action verb, the subject performs the action denoted by the verb. As the subject does or acts upon the verb, the sentences are said to be in the active voice. However, one can change the canonical word order of a sentence so that subject is no longer active, but being acted upon by the verb, as the original version of the sentence above shows.
In the sentence above, the construction with the passive voice is <em>a broken window was created.</em> As you can see, the direct object has been moved to the subject slot and an auxiliary form of the verb <em>to be</em> has been introduced. For the sentence to be active again, you should introduce the doer of the action, the one that discovers the broken window (we). That is why the revision contains the personal pronoun in question.
