1.After our guests had (ate, eaten), we all toured the city.

2.He (did, done) the experiment that very afternoon.

3.Lenny had never (drove, driven) a tractor before that day.

1.eaten
2.did
3.driven

All correct -- nice!

1. After our guests had eaten, we all toured the city.

2. He did the experiment that very afternoon.
3. Lenny had never driven a tractor before that day.

To determine the correct verb form in each sentence, we need to consider the verb tense and the subject of the sentence.

1. "After our guests had (ate, eaten), we all toured the city."
In this sentence, the guests are the subject. We need to use the past participle form of the verb because the action of eating happened before the touring of the city. The past participle form of "eat" is "eaten." So, the correct answer is "eaten."

2. "He (did, done) the experiment that very afternoon."
In this sentence, the subject is "he." We want to use the past tense of the verb "do." The past tense form of "do" is "did." So, the correct answer is "did."

3. "Lenny had never (drove, driven) a tractor before that day."
In this sentence, the subject is "Lenny." We want to use the past participle form of the verb "drive" because it is used in a past perfect tense. The past participle form of "drive" is "driven." So, the correct answer is "driven."

To determine the correct verb form, it's helpful to know the different forms of irregular verbs. In these examples, "eat" is an irregular verb, "do" is a regular verb, and "drive" is an irregular verb.