I remember learning this and i think 4 out of 5
A. A UNIT OF ENERGY SUPPLIED BY FOOD.
A calorie is a unit of energy. Historically, scientists have defined "calorie" to mean a unit of energy or heat that could come from a variety of sources, such as coal or gas. In a nutritional sense, all types of food — whether they are fats, proteins, carbohydrates or sugars — are important sources of calories, which people need to live and function.
The median age of onset for bipolar disorder is 25 years (National Institue of Mental Health), although the illness can start in early childhood or as late as the 40's and 50's. An equal number of men and women develop bipolar illness and it is found in all ages, races, ethnic groups and social classes.
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.
