Revise each of the following sentences, filling in the blank with the an appropriate pronoun. Draw an arrow from the pronoun to its antecedent.

1. The students are going ___ first trip to the fire station.
2. Julie and Sara brought ___ notebooks on the trip.
3. Same remembered to bring ___ lunch money.
4. The class listened as the firefighters explained how ___ use special equipment to put out fires.
5. Each piece of equipment has ___ own special function.

My answers to these questions are the following:
1. The students are going on their first trip to the fire station.
Antecedent: students.
2. Julia and Sara brought their notebooks on the trip.
Antecedent: Julia, Sara.
3. Sam remembered to bring his lunch money.
Antecedent: Sam.
4. The class listened as the firefighters explained how they use special equipment to put out fires.
Antecedent: ?
5. Each piece of equipment has its own special function.
Antecedent: equipment.

1: *on

5. The pronoun is they. Who uses special equipment to put out fires?

The rest are right.

Do you mean it is the antecedent of my fourth question?

I'm sorry -- I made a typo. Yes, I was referring to number 4.

But shouldn't the antecedent of my fourth question be "firefighters?" "they" is already the pronoun.

Or is it "class?"

4. The antecedent is firefighters. The class doesn't put out fires (I hope.)