Correct the mistakes in the sentences shown in the image.

Here are the corrections for the sentences: 1. He is a student. (Correct) 2. Are you ready? (Correct) 3. The boys are my friends. (Correct) 4. Where is she? — She is in the park. (Corrected: "Where she is?" corrected to "Where is she?") 5. How old are you? — I am fine. (Correct) 6. I am not at school. (Corrected: "I not at school" corrected to "I am not at school.") 7. They are not friends. (Corrected: "They not friends" corrected to "They are not friends.")