Heat causes the（）of gas.

A . remain constant along the tubes length B . be greatest in a single pass counter flow heat exchanger C . remain constant throughout the heat exchanger D . vary from section to section through out the heat exchanger

A . Develop ductility B . Improve machining qualities C . Relieves stresses D . All of the above

A . (1)+(2) B . (1)+(3) C . (2)+(3) D . (1)+(2)+(3)

A . achromatism or thin gray B . thin white C . sky-blue D . black

A . dry bulb temperature B . wet bulb temperature C . dew point D . dry point

A . cools the inert gas and prevents soot from entering the cargo tanks B . acts as an emergency shutdown when inlet pressures exceed the safe working pressure C . prevents the backflow of hydrocarbon gasses into nonhazardous areas D . relieves sudden large overpressures in the system

A . dry bulb temperature B . wet bulb temperature C . saturation temperature D . water vapor superheat

A . prevent engine back pressure at heavy loads B . increase total engine efficiency at low loads C . prevent boiler corrosion at low engine loads D . improve engine fuel consumption at any load

A . at the compressor discharge B . at the compressor suction C . in the expansion valve D . in the receiver

A . Overcoming sliding friction B . Overcoming rolling friction C . Overcoming fluid friction D . Overcoming oil wedge frictio

A . prevents the flue gas from falling below 3% content of oxygen B . allows the inert gas piping to be used for gas freeing the tanks C . opens when there is excessive vacuum on the deck water seal D . enables outside air to mix with and cool hot flue gasse

A . flash point B . upper explosive limit C . lower explosive limit D . fire point

A . pressure B . toxicity C . temperature D . flammability

A . excessive heat B . insufficient heat C . effective cooling D . high output

A . filter B . cooler C . scrubber D . purifier

A . Scrubber B . Demister C . Deck water seal D . Final filter

A . eliminate hot air from the condenser B . maintain steady pressure in a system C . heat, or cool one fluid by means of another fluid D . reduce the engine room temperature in tropical climate

A . the burning B . the fuel C . the air charge D . the engine pisto

A . radiation B . conduction C . convection D . condo-radiatio

A . conduction B . convection C . radiation D . windage

A．supplies B．receives C．provides D．requires

The first study was done at Duke University in Durham, North Carolina. Researchers pumped extra carbon dioxide into a test area where pine trees were growing. The trees grew thirty-four percent faster during the first three years. However, in time, the trees slowed to about their normal growth rate. The scientists say this is because trees need other nutrients, such as nitrogen. In the second study, researchers from Duke and Bowdoin College in Brunswick, Maine examined the soil around trees. They discovered that as the leaves broke down into the soil, all the carbon was not trapped in the soil. Much of it was released into the atmosphere as carbon dioxide. The findings of the two studies were published last month in Nature magazine. They suggest there is limited value in planting trees to reduce the carbon dioxide pollution in the atmosphere. Forest planting has been a part of negotiations on a world agreement to reduce greenhouse gases that scientists believe cause global warming. The United States, Canada, Japan and some other industrial countries have supported the idea. But this new research suggests the idea is not as effective as environmental activists had thought. Scientist Ram Oren of Duke University led the study on tree growth. He says that earlier estimates on the ability of forests to absorb carbon dioxide were overly hopeful. Some scientists not involved in the studies say the research provides some of the first evidence on how trees react to carbon dioxide. Other scientists say the research disputes a belief among some coal and power companies. The companies say that rising levels of carbon dioxide in the atmosphere will not create harmful global warming. Instead, they say it will increase forests and other plants. What is the purpose of this passage？ A．Introduce some new ideas about the relationship between trees and carbon dioxide. B．Introduce recent condition of global industrial pollution. C．Call on people to plant more trees to reduce greenhouse gases. D．Point out that power companies should be responsible for the rising levels of carbon dioxide.

1.A.number B.group C.price D.deal 2.A.effect B.amount C.course D.program 3.A.increase B.increasing C.had increased D.is increasing 4.A.without B.improve C.producing D.strength 5.A.key B.a direction C.a solution D.service 6.A.cost B.method C.branch D.pound 7.A.Show B.pay C.save D.produce 8.A.property B.remedy C.welfare D.movements 9.A.So that B.which C.whose D.Of which 10.A.at B.for C.In D.from