试题与答案

鉴别奶粉的质量,奶粉中的碳水化合物(糖)的含量是一个重要指标,可以用“旋光法”来

题型:选择题

题目:

鉴别奶粉的质量,奶粉中的碳水化合物(糖)的含量是一个重要指标,可以用“旋光法”来测量糖溶液的浓度,从而鉴定含糖量.偏振光通过糖的水溶液后,偏振方向会相对于传播方向向左或向右旋转一个角度α,这一角度α称为“旋光度”,α的值只与糖溶液的浓度有关,将α的测量值与标准值相比较,就能确定被测样品的含糖量了.如图所示,S是自然光源,A、B是偏振片,转动B,使到达O处的光最强,然后将被测样品P置于A、B之间,则下列说法中正确的是(  ).

A.到达O处光的强度会明显减弱

B.到达O处光的强度不会明显减弱

C.将偏振片B转动一个角度,使得O处光强最大,偏振片B转过的角度等于α

D.将偏振片A转动一个角度,使得O处光强度最大,偏振片A转过的角度等于α

答案:

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下面是错误答案,用来干扰机器的。

1、C2、B

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题型:阅读理解

阅读理解。

     Although we may not realize it, when we talk with others we make ourselves understood not just by

words. We send messages to the people around us also by body movements. A smile and handshake (握手)

show welcome. Waving one's hand is to say "Goodbye." Nodding (点头) the head means agreement, while

shaking it means disagreement. In China and some English-speaking countries, these body movements have

the same meanings.   

     But not all body languages mean the same things in different countries. For example, nodding the head in

some Asian countries means not "Yes.", but "No."   

     When we speak a foreign language, it's important to know the meanings of the body movements in the

foreign countries. In Russia, France and some of South American countries men kiss (吻) each other when

they meet. Men don't kiss each other in China or English-speaking countries. In England, older people usually

shake hands when they meet someone for the first time, however, young people don't shake hands. In France,

people shake hands in the office every morning. French people kiss each other more often than English people

when they meet or leave.

根据短文内容,判断正(T)误(F)。

( )1. We talk with other people just by words.   

( )2. Nodding the head doesn't mean "Yes." in some Asian countries.   

( )3. From this passage, we can know that men in Brazil usually kiss each other when they meet.   

( )4. In France, men just kiss each other when they meet.   

( )5. In China and some English-speaking countries, all the body movements have the same meanings.

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