问题
单项选择题
无法避免离心泵产生气缚的措施有()。
A、泵底阀无泄漏
B、叶轮干净无堵塞
C、吸入口直径大于泵入口直径
D、泵吸入口堵塞
答案
参考答案:D
无法避免离心泵产生气缚的措施有()。
A、泵底阀无泄漏
B、叶轮干净无堵塞
C、吸入口直径大于泵入口直径
D、泵吸入口堵塞
参考答案:D
完形填空。 | ||||
Mr Smith has a great sports collection. He has___1___basketball. He has___2___baseballs. He has three soccer balls___3___three___4___.He likes(喜欢)sports very much. He___5__ sports everyday.___6___his son likes___7___,too. He___8___a great sports collection, too. He often plays___9___ soccer with___10___friend, Tom. | ||||
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