英语四级全真预测试卷及答案-选词填空

　　Part IV Reading Comprehension

　　Section A

　　Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the center. You may not use any of the words in the bank more than once.

　　Questions 47 to 56 are based on the following passage.

　　Perhaps like most Americans you have some extra pounds to 47 . You may even have tried a fad diet or two, but found yourself right back where you started. The key to weight loss is regular 48 activity. And surprisingly, you dont have to give up eating or make the gym your second home to see long-term, 49 effects.

　　You body needs a certain amount of energy to maintain basic 50 such as breathing, blood circulation and digestion. The energy required to keep your organs functioning is referred to as the resting or basal metabolic rate.

　　Any time you are active, 51 energy is required. It is obtained from glycogen and fat stored in the blood, liver, and muscles. The key to losing weight is to draw on the fat rather than on the carbohydrate reserves.

　　Which of the two energy sources you use depends on the intensity and 52 of your activity. The higher the intensity, the more your body will pull from the stored carbohydrates. The lower the intensity, the more your body will 53 on fat as its fuel.

　　Aerobic exercise is most 54 for weight loss. When you perform aerobic activities you 55 contract large muscle groups such as your legs and arms. Walking, running, rollerblading, swimming, dancing, and jumping jacks are all forms of aerobic activity.

　　Surprisingly, if your aerobic activity is low to moderately intense and of long duration, you will burn more fat than if you had 56 in a short burst of high-intensity exercise. In short, a brisk 30-minute walk will burn fat while a 100-yard sprint will burn glycogen.

　　 positive

　　 additional

　　 duration

　　 effective

　　 shed

　　 physical

　　 food

　　 functions participated

　　 rely

　　 cut

　　 repeatedly

　　 uses