9. The survey results also indicate that a shuttle service every 20 minutes would be _____ for students.desirabledesireddesiringto desire

To fill in the blank in the sentence appropriately, we need to consider the context and grammatical structure of the sentence.

Analyzing the Options

1. Desirable: This is an adjective that describes something that is appealing or wanted.
2. Desired: This is the past participle of the verb "desire," used as an adjective but may suggest something already desired rather than something beneficial.
3. Desiring: This is the present participle of the verb "desire," which can imply an ongoing action.
4. To desire: This is an infinitive form of the verb, which doesn’t fit the structure of the sentence.

Conclusion

The most appropriate word to fit in the blank is "desirable," as it correctly describes the shuttle service as being something that would be attractive or beneficial to the students.

Final Answer

The sentence should read: "The survey results also indicate that a shuttle service every 20 minutes would be desirable for students."