Which of the following is true about biofuels?
a. they are made from plant materials and animal fats.
b. they are made by directly harnessing energy from the sun.
c. they use energy from water.
d. they use energy from the earth���s core.

image result for how many calories of energy will 20 grams of carbohydrates provide in one gram provides 4 calories

consuming the right balance of protein, carbohydrates and fat can you maintain a healthy weight and optimize your energy levels. protein and carbohydrates both contain 4 calories per gram, while fat provides 9 calories per gram.