Question

the necklace was not stolen by celestine(turn to active voice)

Answer 1

This is Past Simple Tense case. The dynamic voice is composed utilizing Past Simple shape the verb (V2).

The aloof voice is composed utilizing was/were+Past Participle (V3).

Since the given sentence is a negative sentence we will utilize the did+not+V1 type of the verb.

Henceforth the right answer is given beneath: Celestine did not take the neckband.

Answer 2

=> Celestine did not steal the necklace.