单选题Which of the following statements is FALSE concerning cranes being installed on the centerline of vessels（）.A A centerline crane can never be operated in tandemB One crane is able to work one end of two adjacent hatchesC These cranes are more economica

Energy can be created or destroyed

Energy may not be transformed

The total quantity of energy in the universe is always the same

None of the above

Cargoes are any type of goods transported by any type of ships

Cargoes are goods transported in bulk

Cargoes usually include goods transported in bulk and in containers

Cargoes are usually packaged in containers

Special tools are required for lapping or grinding

It is impossible to throttle flow with a butterfly valve

To close the valve, it is only necessary to turn the handle a quarter of a turn

The butterfly valve should never be used in a freshwater system

The cranes may be operated independently

The cranes may be interconnected for twin operation

The cranes are powered by independent internal combustion power units

All of the above

High conductivity of the distillate indicates distillate salinity is excessive

Increasing the absolute pressure of the shell will increase the distillers capacity

Mesh separators are used in evaporators to filter the distillate

Reducing the brine density will reduce the heat lost overboard

The cetane number affects the amount of injection lag

The cetane number is an indication of the fuels viscosity

Ignition lag is reduced with fuels having a high cetane number

The cetane number is of little significance in the combustion process

It is lower than the ignition temperature

It is the temperature at which a substance will spontaneously ignite

It is the temperature at which a substance, when ignited, will continue to bum

It is the temperature at which the released vapors will fall within the explosive range

The greater the atomization, the greater the penetration

The greater the atomization, the less the penetration

The degree of atomization has nothing to do with the degree of penetration

Atomization and penetration are one and the same

Surrounding the fixed shaft is a hollow shaft

This hollow shaft carries radial bores

Each bore is fitted with a well-lapped plunger

There are always even numbers of bores

The discharge is slow due to the size of the cargo and all the cranes working together

The cargo discharge can be accomplished with controlled pendulation

The cargo discharge can be performed in port or at anchor

The cranes enable the handling of heavy cargos without shoreside assistance

c=d

l and k are parallel

m and l are perpendicular

The cranes may be operated independently

The cranes may be interconnected for twin operation

When twinned，the crane rotation on the foundation assembly is unlimited

All of the above

Radio communications allow the crane operator to disregard the use of hand signals

The crane operators and signalman must be familiar with the correct hand signals

The forward cranes can be operated from the bridge

The aft cranes can be operated from the aft steering station

They are particularly suited for pumping high viscosity fluids

They are started with the discharge valve opened

The flow of liquid is developed by imparting energy due to the rotation of an impeller

They are always mounted in a horizontal position

Combustion gases flow through the tubes

Flames impinge on the tubes

Combustion occurs in the tubes

Water flows through the tubes

 The defragfs command should not be run against file systems and logical volumes that contain mostly transitory information， such as /tmp.

 The defragfs command should not be run on a large JFS2 file system when running on a 32-bit kernel.

 The defragfs command can improve file system performance by increasing the file system’s contiguous free space.

 The defragfs command can only be run against file systems that are mounted with read-write permissions.

The oil temperature is less than the cooling water temperature

The oil pressure is less than the cooling water pressure

The oil pressure is greater than the cooling water pressure

The oil flow control valve is always installed in the oil input line

The agent is considered nontoxic at room temperature in low concentrations

The agent is less effective than carbon dioxide

Halon primarily extinguishes the fire by cooling

The agent cannot be used on electrical fires because it leaves a residue

Viscosity will increase as temperature increases

Viscosity is a measure of a fluid s internal resistance to flow

Viscosity will decrease as temperature decreases

Viscosity is not dependent on temperature