【多选题】空气压缩机系统中储气罐(或缓冲罐)的作用是()。
【单选题】钢筋混凝土梁截面抗弯刚度随荷载的增加及持续时间增加而
【单选题】在东北旅游区, 有 “东方底特律”之称的城市是
【单选题】I have worked with him for some time and have found that he is ________ than Jim.
A.
more efficiently a worker
B.
a more efficient worker
C.
more an efficient worker
D.
a worker more efficient
【单选题】I have worked with him for some time and have found that he is ________ than John.
A.
more efficiently a worker
B.
a more efficient worker
C.
more an efficient worker
D.
a worker more efficiently
【单选题】下列有关气压给水设备工作原理的叙述中错误的是( )
B.
气压给水设备是根据在定温条件下,一定质量的气体的相对压力和它所占的体积成反比的原理制造的
C.
在供水过程中,单罐定压式气压给水设备罐内的水压始终处于表化状态
D.
气压给水设备是利用密封罐中压缩空气的压力变化发挥增压和水量调节作用
【简答题】设sinx 2 为f(x)的一个原函数,求∫x 2 f(x)dx