问题
单项选择题
磁路定律可由（）来证明其正确。
A.描述磁场性质的磁通连续性原理；
B.安培环路定律；
C.描述磁砀性质的磁通连续性原理和安培环路定律；
D.磁路欧姆定律。
答案
参考答案：C
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磁路定律可由（）来证明其正确。
A.描述磁场性质的磁通连续性原理；
B.安培环路定律；
C.描述磁砀性质的磁通连续性原理和安培环路定律；
D.磁路欧姆定律。
参考答案：C
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| What do you know about the sea (大海)? Some people often see it, __1__ the others don't. The sea looks __2__ on a fine sunny day. Millions of people hope to take their __3__ by the sea. They can swim in it, or lie on the beaches in the sun. They __4__ themselves there. But it can be very rough (猛烈) when there is a strong wind. What other things do we know about it? Of course, the sea is very large. Looking at a __5__ of the world, you can see it is much bigger than land. There are a lot of __6__ in the sea. Some of them are big and the others are __7__. Did you swim in the sea? If you answer "Yes", you may know that the water is salty (咸的). Rivers carry __8__ from the land to the sea. Some places of the sea are more salty than other places. Do you know the Dead Sea (死海)? Fish __9__ live in it. And people can easily swim in it. Nobody is afraid to __10__ in the water. | ||||
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