水泵在标准状况下即水温（）时，泵轴旋转时泵所允许吸上的最大真空高度，叫允许吸上真空高度。
参考答案：20℃一个大气压
Mr．Smith was very glad _____ as the manager of the company．
A．being appointed
B．having appointed
C．to have appointed
D．to have been appointed
排卵性功血多见于()
A．青春期与围绝经期妇女
B．育龄期妇女
C．老年期妇女
D．流产后妇女
E．不育患者
