Removing hardness of water by lime water

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.

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.