Here's why:
* Predicate: The part of a sentence that tells what the subject does or is.
* Complete Predicate: Includes the verb and all the words that modify the verb, including objects, complements, and modifiers.
In this sentence:
* Subject: Daedalus and his son Icarus
* Verb: were imprisoned
* Object: a great race
Therefore, the complete predicate encompasses the verb "were imprisoned" and the object "a great race".