The process of gaining or losing weight can be explained by comparing your body to your ca
For the purpose of this comparison, 【B7】______ , there is one significant difference between them. Your car cannot store fuel by turning it into 【B8】______ else; all gasoline not 【B9】______ remains as gasoline. But your body stores 【B10】______ energy as fat. When the gas tank is 【B11】______ empty, the car won't run; but your body can burn fat to provide more energy.
Therefore, if you want to gain weight, you must do 【B12】______ of two things: eat more calories (units of heat, therefore energy), or use less through 【B13】______ . If you want to lose weight, you do the 【B14】______ , decrease your intake of calories or increase the amount of energy you spend. There is 【B15】______ way. Gaining or losing weight is always a relation between intake and output of potential energy.
【B1】______
A.in
B.on
C.for
D.against