The panther paused to sniff the humid night air. It heard noises up ahead, but it did not recognize the sounds. The strange noises continued, and the panther became frightened. The panther crept into a cave because it was afraid

The missing question is Which sentence from the passage is complex?

The answer is: The panther crept into a cave because it was afraid.

Explanation:

A complex sentence has an independent clause and one or more dependent clauses. Independent clauses are the ones that have meaning on their own so, they can stand alone as sentences. On the other hand, dependent clauses can not stand alone; they need the support of another clause to make sense.

In the sentence "The panther crept into a cave because it was afraid." the independent clause is The panther crept into a cave while the dependent clause is because it was afraid. The word "because" is subordinating conjunction since it is a word that connects the two clauses.

the objective should be switched