Final answer:
The missing word in the student's sentence should be an adjective describing the most noticeable flavor in the punch, which is 'dominant'. The completed sentence states the dominant flavor of the punch is strawberry.
Step-by-step explanation:
The sentence provided by the student needs to be completed with an adjective that describes the dominant flavor of the punch. When a punch is made from a variety of flavors, but one taste stands out the most, we usually describe that taste as being the "dominant," "primary," or "prevailing" flavor. Therefore, the adjective that best fits the blank in the sentence would be "dominant."
The complete sentence would then read: "Although the delicious punch is made of a mixture of fruit juices, the dominant flavor is strawberry." This sentence indicates that although there are many flavors in the punch, the flavor of strawberry is the most noticeable or powerful among them.