The answer is the G1 checkpoint
The feature of the bone tissue which allows it to normally withstand lateral stress without it giving or breaking up. Because the bone which receives the most impact, each opposite side stretches, and last but not the least bones are able to cancel them out themselves.
Well it depend what science are u talking about.
Physic would require algebra and something about graph (Reading graph)
Biology would require graphing and simple add and subtracting
Chemistry would require graph and know how each atom react to each other. <span />