【单选题】One of the main functions of wearing rings, as used in a centrifugal pump, is to _____.
A.
maintain radial alignment between the pump impeller and casing
B.
absorb all impeller shaft end thrust
C.
prevent water leakage to the atmosphere
D.
prevent wear of the pump casing and/or impeller
【单选题】在C语言中,以下叙述不正确的是:
A.
在C程序中,无论是整数还是实数,都能被准确无误的表示
【单选题】The ____pump is usually used as the emergency bilge pump.
【单选题】以下正确的叙述是( )
B.
若a是实型变量,C程序中允许赋值a=10,因此实型变量中允许存放整型数
C.
在C程序中,无论整数还是实数,都能被准确无误的表示
【简答题】A solar pump(太阳能水泵 ) was built in a desert small village. The pump used the deserts most common resource – sunlight, to increase its greatest need, water. Solar collectors were used to collect the sun...
【单选题】The lube oil pump used in a diesel engine is a ().
【单选题】在 C 语言中 , 以下叙述不正确的是
A.
在 C 程序中 , 无论是整数还是实数 , 都能被准确无误的表示
B.
在 C 程序中 , 变量名代表存储器中的一个位置
【单选题】在C语言中,以下叙述不正确的是
A.
在 C 程序中 , 无论是整数还是实数 , 都能被准确无误的表示
B.
在 C 程序中 , 变量名代表存储器中的一个位置
D.
一个 C 语言的执行是从程序的主函数开始 , 到程序的主函数结束
【单选题】The purpose of the wearing rings used in a centrifugal pump is to ().
A.
prevent an internal explosion in the pump when it is overheated
B.
enable a visual inspection of the pump while it is running
C.
insure a proper alignment of the pump coupling to the driver
D.
accommodate for friction between the impeller and the easing
【单选题】On a ship,a fire pump may be used for other purposes if().
A.
the other services are run off a reducing station with a pressure gage
B.
a separate fire pump is available for use on the fire main
C.
all other services are operated by a manifold near the pump