A-A+ A gear pump belongs to _____ according to its working principle. 2020-09-18 20:28:24 资格考试 阅读 问题详情 A.reciprocating pumpsB.positive displacement pumpsC.centrifugal pumpsD.centripetal pumps请帮忙给出正确答案和分析,谢谢! 参考答案 查看解答