Final answer:
The sentence 'I don't really care' should be completed with the word 'about' to properly convey indifference. Examples of correct use of similar words in different contexts further illustrate the importance of choosing the right word or form in sentence completion.
Step-by-step explanation:
The correct word to complete the sentence "I don't really care" is about. The proper use of prepositions is essential for the clarity of a sentence, and in this case, 'about' correctly conveys indifference or lack of interest towards something.
Examples:
Can you hear the phone ring from here?
Are you going to the movie theater at two p.m., or is that too early for you?
This show always has a depressing effect on me.
It's hard to find small apartments for rent in this neighborhood.
Let's meet at the pizza place so that I can eat something without meat.