什么叫漩涡泵？
参考答案：
漩涡泵是一种特殊的离心泵，它是靠叶轮在带有不连贯槽道的盖板之间旋转时产生漩涡运动的作用而吸入和排出液体的把那个，所以叫漩涡泵。
阅读下面短文，在空白处填入适当的单词，使短文结构完整，意思通顺、连贯。
每空填写一词。
I go to the cinema a lot. I often go alone, 1_____ sometimes my friend Rose comes,
too. My husband 2_____ comes with me-he is always too busy! I buy chocolates to
3_____ during the film. I usually 4_____ these night films very much. I don't want to
see the 5_____ film twice, but sometimes I do if it's really good.
改变物体的质量和速度大小，都能使物体的动能发生变化。欲使物体的动能变为原来的2倍，可以采取的方法是 [ ]
A．质量不变，速度增大到原来的2倍
B．速度不变，质量增大到原来的2倍
C．质量减半，速度增大到原来的4倍
D．速度减半，质量增大到原来的4倍
