Answer:
1 His mom finally peered through the cracked door that Johnny normally kept locked.
Step-by-step explanation:
The topic sentence introduces the subject and makes a summary of the paragraph it is included in. Besides, it is typically placed at the beginning of the paragraph. In the text given, the topic sentence presents the argument the paragraph will deal with, which is Johnny's bedroom. Thus, the rest of the sentences describe the room from her mother's point of view, which supports the topic sentence, and provides a conclusion.