Answer:
B. Sternum
Explanation:
The sternum (or breastbone) is a flat bone in the thorax's anterior area. It has a 'T' shape and is located in the center of the chest. The sternum, which is part of the bony thoracic wall, protects the internal thoracic viscera, such as the heart, lungs, and oesophagus.
Here is a picture from the internet.
Answer:
D.
Explanation:
The periodic table is divided into vertical periods and horizontal groups
A. Stretching your legs before a run. You're creating tension by applying force to pull your tendons and ligaments.
Do you mean ion pumps in the membrane of cell?
If so, then ion pumps maintain an electrochemical gradient across the membrane.