Question

determine word meanings using known words and prefixes in-/im- and mid- — instruction — level c break the word into its prefix and base word. incomplete

Explanation:

To break "incomplete" into prefix and base word, we identify the prefix (a word part added to the start of a base word) and the base word (the main part of the word). The prefix "in - " (here as "in" in "incomplete") means "not", and the base word is "complete". So we separate the prefix "in" from the base word "complete".

Answer:

Prefix: in; Base word: complete