证券投资基金根据组织形态的不同，可分为（）。

A.high pressure liquid

B.low pressure vapor

C.high pressure vapor

D.low pressure liquid

d also from a vapor into liquid with a reasonably narrow range of pressure？

A.Refrigerator

B.Refrigerant

C.Cooling medium

D.Brine

tem is sufficiently chargedIt is generally located in the _____.

A.high pressure liquid line

B.low pressure liquid line

C.high pressure vapor line

D.low pressure vapor line

es of vapor, containing millions of molecules, form. below the surface. In order for such bubbles to be produced, the pressure of the vapor inside them must be equal to the pressure of the air upon the surface of the liquid. If the air pressure is greater, the bubble will collapse. The boiling point of a liquid, then, is the temperature at which the vapor pressure of the liquid is equal to the atmospheric pressure upon the liquid at the surface.

The pressure of the atmosphere at sea level is about one kilogram per square centimeter. We call this pressure one atmosphere. The boiling point of a liquid, therefore, is the temperature at which its vapor pressure equals one atmosphere. The boiling point of water is 100 Celsius; of ethyl alcohol 78.5 Celsius; of mercury, 356.9 Celsius.

If the pressure on the surface of the water is reduced, the boiling point will be lower. Now the higher up we go from sea level, the lower the atmospheric pressure becomes, since there is less air to press upon us. Hence, while water boils at sea level at a temperature of 100 Celsius, its boiling point on a mountain three kilometers high is only 90 Celsius. Since the temperature of water does not rise as a result of boiling, it would take you longer to cook potatoes or carrots in boiling water on the mountain than it would at sea level.

The liquid boils only when ______.

A．the temperature is raised

B．the bubbles of vapor form. below the surface

C．the temperature of the liquid is raised enough

D．the temperature of the liquid is near 100 Celsius

Reid vapor pressure is ______．

A.exerted by liquid cargo on the sides of a tank

B.exerted by liquid cargo on a cargo hose body

C.the lowest temperature and pressure that will cause a flammable liquid to give off vapors

D.a measurement of the amount of flammable vapors given off by a liquid at a certain temperature

The refrigerant leaves the evaporator of a refrigeration system as a low pressure _____.

A.sub-cooled liquid

B.high temperature liquid

C.oil saturated liquid

D.superheated vapor

A．I only

B．II only

C．Both I and II

D．Neither I nor II

Evaporation rates of hydrocarbon liquid from horizontal surfaces are approximately given by

Where p is vapor pressure of the liquid and P is the atmospheric pressure. We have spilled a layer of lubricating oil on a metal drip pan in our garage. It forms a layer 1 mm thick. Its density is 1g/cm³and its molecular weight is 400 g/mol. Its vapor pressure is approximately 10^-7torr at 20℃. Estimate how long it will take all of this motor oil to evaporate at 20℃.