2009年12月英语四级考试模拟训练及答案(一)

　　Vitamins B

　　B group vitamins have a wide range of roles acting as co-enzymes in metabolic pathways. They are found in most plant and animal tissues involved in metabolism, therefore foods such as liver, yeast and dairy products are all rich in B group vitamins. Deficiency of B group vitamins include dermatitis, fatigue and malformation of red blood cells.

　　1. An adult needs about 12,000kJ of energy a day from ________.

　　A. the cell B. the respiring process of carbohydrates

　　C. fats in the cell D. a balanced diet

　　2. Carbohydrates are ultimately absorbed into cells in the process of _______.

　　A. digestion B. respiration

　　C. oxidization D. mobilization

　　3. The Essential Amino Acids which build part of proteins can be obtained from______.

　　A. stomach B. body tissues

　　C. the body D. the diet

　　4. The ultimate cause of kwashiorkor is lack of ________.

　　A. protein B. carbohydrates

　　C. vitamins D. diet

　　5. Vitamins are called “micronutrients” in that _________.

　　A. excessive fat soluble vitamins can be excreted in the urine B. the body only requires small amount of vitamins

　　C. a dose of 3300mg of vitamins can be considered toxic D. the high concentrations of water soluble vitamins are toxic

　　6. Night blindness is a disease normally caused by lack of __________.

　　A. fat soluble vitamins B. water soluble vitamins

　　C. vitamin A D. innate disability

　　7. The main function of vitamin D is to prevent adults from ________.

　　A. the growth of strong bones B. fracture

　　C. a progressive softening of the bones D. calcium uptake from the gut

　　8. Although the human body produces vitamin D normally, it fails to do so if there is not enough ______________.

　　9. The reason why vitamin C is seen as an antioxidant is that it drives __________ out of the body.

　　10. If you are in lack of B group vitamins, you should turn to _______________.