离心泵中的机械密封是用来防止（）与机体之间流体泄漏的密封。
A、电机
B、轴承
C、旋转轴
D、叶轮
参考答案：C
My brother is really___ . He often works in his office far into the night. [ ]
A. open-minded
B. hard-working
C. self-confident
D. warm-hearted
张永平对消防安全处的处罚行为不服时应向谁申请复议
