Avoiding secondhand smoke can help prevent lung cancer.
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.
Answer:
a major city together with its suburbs and nearby cities, town, and environs over which the major city exercise a commanding economic and social influence.
