Question

insert dashes where needed.
elephant keepers in zoos take great care when introducing elephants highly intelligent animals with a complex social structure to new keepers or new herds.

Explanation:

Dashes are used here to set off a parenthetical descriptive clause that adds extra information about elephants, interrupting the main sentence flow for clarification.

Answer:

Elephant keepers in zoos take great care when introducing elephants—highly intelligent animals with a complex social structure—to new keepers or new herds.