齿轮泵消除困油现象也可以用对称结构的圆形卸荷盲孔。() 发布时间:2017-09-01 00:22 │ 来源:www.tikuol.com 题型:判断题 问题: 齿轮泵消除困油现象也可以用对称结构的圆形卸荷盲孔。()
题型:判断题 ---Is Mary still performing?----I’m afraid not. She is said_____ the stage already.A.to have leftB.to leaveC.to have been leftD.to be left 查看答案