The stress? Bad eating habits due to lack of money and time? There could be lots of reasons but that's what came to mind first.
Answer:
Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. As the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.
The most likely reason for death for someone born in 1900 was caused by Influenza and pneumonia. The most likely causes for death for some one born in 2006 is congenital malformations.
I didn't quite understand what do you mean but if you mean what items uses triangle, some examples are: ladder, folding chair and everything that be fold that are supports
