Final answer:
Sentence 4, "They had been driving for hours before they found a hotel," does not include a gerund because "driving" is part of the verb phrase indicating a past action rather than acting as a noun.
Step-by-step explanation:
The student has asked which sentence does not use a gerund. A gerund is an -ing form of a verb that functions as a noun, which can be part of a gerund phrase.
Sentence 4, "They had been driving for hours before they found a hotel.", does not include a gerund. Here, "driving" is part of a past perfect continuous tense verb phrase, indicating an action that was happening over a period of time in the past, rather than functioning as a noun.
On the other hand, sentences 1, 2, and 5 all contain gerunds: "eating" in sentence 1, "smelling" in sentence 2, and "shouting" in sentence 5 are all -ing forms functioning as nouns, and not as verbs creating a progressive verb tense as seen in sentence 4.
The sentence that does not use a gerund is: "They had been driving for hours before they found a hotel." In this sentence, the verb "driving" is not functioning as a noun, but as the main verb of the sentence.
Sentence 4, "They had been driving for hours before they found a hotel,"