Read the following passage and choose the best answer for each blank.

We need calories or (1) ____ to do the things every day. For example, when we walk to school or (2) ____  a bike to school, we use a certain amount of calories and (3) ____ when we sleep, we also use them. But how many calories should we (4) ____ a day to stay in shape? It’s difficult (5) _____ us to calculate. If people want to keep (6) ____, they should remember that everyone should have between 1,600 and 2,500 calories a day. We get calories from the food we eat. If we get too much food and don’t take part (7) ____ any activities, we can get fat quickly. (8) _____ besides studying, we should do some exercise, play sports or do the housework (9) _____ cleaning the floor, cooking etc., If we don’t eat (10) _____ , we feel tired and weak.

But how many calories should we (4) ____ a day to stay in shape?