[{"id": 1, "type": "multiple_choice", "options": ["NaCl", "CO₂", "O₂", "H₂O"], "question": "What is the chemical symbol for water?", "correct_answer": "H₂O"}, {"id": 2, "type": "multiple_choice", "options": ["O₂", "NaCl", "CO₂", "H₂O"], "question": "What is the chemical symbol for water?", "correct_answer": "H₂O"}, {"id": 3, "type": "multiple_choice", "options": ["Always accelerate", "Eventually start moving on its own", "Stay at rest unless acted upon by an external force", "Change direction randomly"], "question": "According to Newton's First Law, an object at rest will:", "correct_answer": "Stay at rest unless acted upon by an external force"}, {"id": 4, "type": "multiple_choice", "options": ["NaCl", "O₂", "H₂O", "CO₂"], "question": "What is the chemical symbol for water?", "correct_answer": "H₂O"}, {"id": 5, "type": "written_response", "question": "Explain the scientific concept covered in \"Ecosystems Practice\" and provide a real-world example.", "correct_answer": null}]