问题 问答题 简答题

《内河航道及港口内船舶辐射噪声的测量》(GB/T4964—1985)中,对传声器的位置是如何规定的?

答案

参考答案:

传声器应放在码头、岸边或测量船上,高度距站立面1.2~1.5m,最好高出水面3~6m之间,传声器的方向要垂直于船舶的航向。

当被测量船舶通过传声器正前方时,船的舷侧与传声器的基准距离最好为25m,偏离此距离时应按规定进行修正。在验收试验时距离应尽可能在20~35m之间。

阅读理解

阅读理解

     Have you ever been ill ? When you are ill , you must be unhappy because your body becomes hot ,     and there are pains all over your body . You don’t want to work , you stay in bed ,feeling very sad.

     What makes us ill ? It is germs(细菌).Germs are everywhere. They are very small and you can’t       

find them with your eyes, but you can see them with a microscope. They are very very small and there       could be hundreds of them on a very small thing.  

     Germs are always found in dirty water. Water under the microscope, we look at dirty water unde

 the microscope, we shall see them in it .So your father and mother will not let you drink dirty water.

     Germs aren’t found only in water. They are found in air and dust .If you cut your finger, if some

of  the dust from the floor goes into the cut (割开处), some of the germs would go into your finger.

Your finger would become big and red , and you will have much pain in it .Sometimes the germs would

go into all of your body , and you would have pain everywhere.

1. Which of the following is true?

    A. If things are very very small, they are germs.

    B. If things can’t be seen , they must be germs.

    C. Germs are only in dirty water.

    D. Germs are everywhere around us.

2. What is a microscope used for?

    A. Making very very small things look much bigger.

    B. Making very big things look much smaller.

    C. Helping you read some newspapers.

    D. Helping you if you can’t see things clearly.

3. Why don’t your parents let you drink dirty water?

    A.You haven’t looked at it carefully.

    B. Water can’t be drunk in this way.

    C. There must be lots of germs in it .

    D. Water will make you ill .

4. Which of the following is not true?

    A. Germs can be found both in water and in the air.

    B. Germs can go into your finger if it is cut.

    C. If your temperature is not OK, there must be germs in your body.

    D. If your finger isn’t cut , there aren’t any germs on it.

5.What’s the main idea of the passage?

   A. Germs may make us ill.

   B. Germs are in dirty water.

   C. Don’t drink dirty water.

   D. Take care of your fingers

单项选择题 A1型题