The vitamins necessary for a healthy body are normally supplied by a good mixed diet(饮食), including a variety of fruits and gree

admin2016-08-30  37

问题     The vitamins necessary for a healthy body are normally supplied by a good mixed diet(饮食), including a variety of fruits and green vegetables. It is only when people try to live on a very restricted diet that it is necessary to make special provision to supply the missing vitamins.
    An example of the dangers of a restricted diet may be seen in the disease known as " beriberi" . It used to distress large numbers of Eastern peoples who lived mainly on rice. In the early years of this century, a scientist named Eijkman was trying to discover the cause of "beri-beri". At first he thought it was caused by a germ. He was working in a Japanese hospital, where the patients were fed on polished rice which had the outer husk(外壳)removed from the grain. It was thought this would be easier for weak and sick people to digest.
    Eijkman thought his germ theory was confirmed when he noticed the chickens in the hospital yard, which were fed on leftovers(剩饭)from the patients’ plates, were also showing signs of the disease. He then tried to isolate the germ, but his experiments were interrupted by a hospital official , who declared that the polished rice, even though left over by the patients, was too good for chickens. It should be recooked for the patients, and the chickens should be fed on cheap rice with the outer layer still on the grain.
    Eijkman noticed that the chickens began to recover on the new diet. He began to consider the possibility that eating unpolished rice somehow prevented or cured "beri-beri" —even that a lack of some element in the husk might be the cause of the disease. Indeed this was the case. The element needed to prevent " beri-beri" was shortly afterwards isolated from rice husks and is now
known as vitamin B. Nowadays, this terrible disease is much less common thanks to our knowledge of vitamins.
The disease "beri-beri"______.

选项 A、kills large numbers of Eastern peoples
B、is a vitamin deficiency(缺乏)disease
C、is caused by diseased rice
D、can be caught from diseased chickens

答案B

解析 本题考查考生的推理判断的能力。A项中的kill是对第二段第二句话中的distress的曲解。C项和D项与文意不符。而根据第二段第一句可知这种病是由限制饮食导致的,而限制饮食会导致维生素缺失,因而“beri-beri”是一种维生素缺乏症。故选B。
转载请注明原文地址:https://jikaoti.com/ti/mRfYFFFM
0

随机试题
最新回复(0)