Pretty good job, I can see you have struggled with placing the boxes for the ribcage and pelvis, mainly with their axes, try to remember how the two masses have an opposing tilt to each other. This means that in the front view you will se bottom plane of the ribcage box, and the top plane of the pelvis box and the opposite is true for the back view! In your fourth page, you nailed the tilt of the pelvis but lost the opportunity to showcase the perspectives of the ribcage! Look at the shoulders, by showing the top plane of the box you would have been much clearer with the perspective. Try using cylinders to showcase the perspective of a pose alongside boxes, it will help you understand whether a form is receding or coming towards you more easily