Question

at the end, a big chunk can split off and make an iceberg. the words split off on page 6 mean ____ to cut with an ax. to run away quickly. to break into parts.

Explanation:

In the context of an ice - chunk separating to form an iceberg, "split off" means to break into parts. It doesn't mean cutting with an ax or running away quickly.

Answer:

to break into parts.