Answer: A large dome-shaped muscle under the lungs called the diaphragm squeezes downward when you breathe in, making a vacuum that causes a rush of fresh air into your lungs. The opposite happens when you breathe out -- your diaphragm relaxes upward, pushing on your lungs, letting them deflate. (A whole explanation from my science book. Hope this helps!)
We can get angry when we are frustrated
Deciding on what is the most important.
Instruction and physical exercises or games especially in school