Answer:
The teeter-totter was shared by the boys.
Explanation:
Passive voice is when the object of the sentence becomes the subject of the sentence. The subject of the sentence then receives the action instead of doing it. Passive voice always includes a form of the verb 'to be' and a particle of the main verb. In the case of the last sentence, the teeter-totter is the object/subject. "Was" is the past tense form of the verb "to be." Shared is the past particle of the verb "share."
So basically, the breakdown is like this:
The teeter-totter + was + shared by + the boys.
object past tense past particle subject
of the verb of the verb
'to be' 'share'
All the other sentences are in active voice as the subject is doing the action. "Lilly took", "Little boy arrived", "The boy started playing" all have the subject in front of the verb.
Hope this helps. :)
It would better improve the paragraph because it has nothin to do with the rest of the paragraph. The paragraph seems to be about team sports and promoting it, while sentence 3 is about individual sports are better then team sports. So removing sentence three would better promote CO-ED team sports.