A. Calories are units of energy. They refer to the What are calories?

Câu hỏi :

A. Calories are units of energy. They refer to the amount of energy you get from foods and drinks, and the amount of energy you use through physical activities. For example, an apple has about 80 calories, while a 1.6 km walk might use up 100 calories. Calories are important for human health, and the key is having the right amount of it.