Câu hỏi:

Read the following passage and mark the letter A, B, C or D to indicate the correct word or phrase that best fits each of the numbered blanks from 26 to 30.

What do we mean when we speak of a calorie? Well, we know that the food we eat is (26) ________ and provides heat. Some foods can provide much heat and other foods provide very little. The foods (27) ________ provide much heat provide many calories. We measure the amount of heat a food provides in calories, just as we measure your (28) ________ in inches or your weight in pounds. A calorie is a measure of the heat required to (29) ________ the temperature of one gram of water one degree centigrade. One calorie of food can also raise one pound of matter to a height of 40 inches. Two thousand calories a day of food in the body can provide a lot of heat and the (30) ________ to do a lot of work.