2019年公共英語四級(jí)閱讀練習(xí)題（3）

　　Vitamins are organic compounds necessary in small amounts in the diet for the normal growth and maintenance of life of animals, including man.?

　　They do not provide energy, 41 do they construct or build any part of the body. They are needed for 42 foods into energy and body maintenance. There are thirteen or more of them, and if 43 is missing a deficiency disease becomes 44 .?

　　Vitamins are similar because they are made of the same elements—usually carbon, hydrogen, oxygen, and 45 nitrogen. They are different 46 their elements are arranged differently, and each vitamin 47 one or more specific functions in the body.

　　48 enough vitamins is essential to life, although the body has no nutritional use for 49 vitamins. Many people, 50 , believe in being on the “safe side” and thus take extra vitamins. However, a well-balanced diet will usually meet all the body's vitamin needs.

　　41. A) either B) so C) nor D) never

　　42. A) shifting B) transferring C) altering D) transforming

　　43. A) any B) some C) anything D) something

　　44. A) serious B) apparent C) severe D) fatal

　　45. A) mostly B) partially C) sometimes D) rarely

　　46. A) in that B) so that C) such that D) except that

　　47. A) undertakes B) holds C) plays D) performs

　　48. A) Supplying B) Getting C) Providing D) Furnishing

　　49. A) exceptional B) exceeding C) excess D) external

　　50. A) nevertheless B) therefore C) moreover D) meanwhile

　　參考答案：CDABC ADBCA?