减少径向力的办法中选用或设计成（）的，它可基本平衡径向力，但

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问题单项选择题

减少径向力的办法中选用或设计成（）的，它可基本平衡径向力，但成本较高，流道制造比较复杂。

A.单蜗壳形式

B.导叶泵体

C.双蜗壳形式

D.同心圆泵体

答案

参考答案：C

听力题

根据下列句子及所给单词的首字母，写出各单词的完全形式（每空限填一词）。

小题1:May is the f________ month of the year.

小题2:When he was young, Mandela decided to f________ for freedom all his life.

小题3:When winter comes, night becomes longer and day becomes s________.

小题4:We should listen to the teacher c________ and take notes in class when necessary.

小题5:Jane likes acting and always d_______ of being a popular actress.

小题6:Don’t believe what he said, he is l________!

小题7:Jack used to rely on his parents, but now he wants to be i_________ from them.

小题8:In China, the Dragon Boat Festival is held in m_______ of Qu Yuan.

单项选择题

下列哪项不是内脏性腹痛的特点

A．疼痛部位含混

B．疼痛部位接近腹中线

C．常伴自主神经兴奋症状

D．腹痛可因体位变化加重

E．疼痛感觉模糊