What does Dr. Michael Alderman say about a randomized, controlled trial?

A．It has been successfully conducted.

B．It should be carried out.

C．It is already under way.

D．It is too late to try it.

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参考答案

答案解析

【定位】第三段第五、六句“What’s needed…but it’s never been done．”。
【答案详解】逻辑推断题。根据第三段第五、六句可知这个实验是“有必要”做的，但目前并没有做，因而B正确。

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1 As stated in the last paragraph, people with normal blood pressure __________.

A．should consider a change of their lifestyle

B．have every reason to be careful about sodium

C．will not be affected by the amount of sodium taken

D．do not have to take sodium too seriously

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2 根据下面资料，回答题
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 "beri-beri". It used to distress large numbers of Eastern peoples who lived mainly on flee. 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 pa-tients 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 offi-cial, 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 ele-ment 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 knowl-
edge of vitamins.
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A．normally contains enough vitamins

B．still needs special provision of vitamins

C．is suitable for losing weight

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3 The disease "beri-beri" __________.

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

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