D. Give reasons for the following. 1. We should always maintain a good posture. Maintaining Good Posture: · Keeps your spine healthy and prevents back problems. · Gives your organs enough space to work well. · Makes you feel more confident and energetic. · Helps you breathe better by allowing your lungs to expand fully. 2. We do not have voluntary muscles in our heart. No Voluntary Muscles in the Heart: · The heart works automatically all the time. · Its muscles are strong and special. · We can't control the heart consciously because it needs to be reliable in pumping blood constantly. · Having involuntary muscles in the heart means we don't have to worry about making it beat – it...