A lightning rod is a metal pole attached to the roof of a house by ____________.

A . tension load twice each crankshaft revolution B . compression load during power and compression strokes C . inertia load once every four crankshaft revolutions D . bending loads at bottom and top dead center

A . the crank-web B . the connecting rod C . the main bearing D . the cross-head

A . piston gudgeon pin B . piston skirt C . cross-head D . cross-head pi

A . becket B . loop C . swivel D . eye

A . bight B . bollard C . chock D . camel

A . From the BIOS, disable the Trusted Platform Module. B . From the BIOS, disable the processor's No Execute feature. C . Start the computer in Safe Mode. D . Start the computer from the Windows Server 2008 R2 installation media.

A . #6 solid copper B . #12 solid copper C . #20 solid copper D . #22 solid copper

A . the hunting gear B . the rudder stock C . the rudder controller D . the feedback unit

A . main bearing shells B . main bearing C . steel D . bearing metal

A . Etch the wire with acid B . Install a wire seizing on the wire that will be inside the socket C . Ensure the fiber core is well lubricated D . Pour molten babbitt metal into the socket

A . the crosshead B . the journals of the crosshead C . the crosshead shoes D . the guide

A . torque wrench B . monkey wrench C . pipe wrench D . slugging wrench

A . along the turn of the bilge B . along each side of the keel C . near the top of the gunwale D . at the bow and at the ster

A . clearance B . crush C . pitch D . thrust

A . inside the bearing B . outside the bearing C . covering the crankshaft D . none of the above

A . erosion B . corrosion C . pitting D . dezincificatio

A . a bolt B . a cap C . a disc D . a nut

A．thus B．because of C．consequently D．in that

A．A.plastic B．B.metal C．C.wood D．D.sand

A．A.melt B．B.must melt C．C.would melt D．D.had melted

David Salt is an expert on plants at Purdue University in West Lafayette, Indiana. He is working with plants that store large amounts of metals. In recent years, scientists have shown interest in using such plants to clean up harmful waste materials. Professor Salt says such plants also could be used to improve people's diets or even to create foods that fight cancer. Humans need a number of metals in their diets, including iron and zinc. These metals are needed in very small amounts, however. That is why they are called micronutrients. The lack of micronutrients is blamed for health problems in many developing countries. Children and pregnant women are mostly affected. Recently, Mr. Salt announced that he has identified and copied the genes from a kind of plant that stores metals in its tissues. He says his study suggests it may be possible to develop plants that contain minerals needed for good health. For example, the metal selenium is a strong anti-cancer agent. Some wild plants store selenium naturally. Mr. Salt says foods to fight cancer might be created if genes from these plants could be moved into crop plants. Locoweed, which is a common plant in the western U.S., stores selenium. Professor Salt says it may be possible to create cancer-fighting foods from it. He and scientists from a company called Unicycle Therapies have copied the gene that causes locoweed to take up selenium from the soil. Many people take pills to add important minerals or vitamins to their diet. However, Mister Salt notes that most selenium products sold in health food stores are of little use. That is because the human body can only take in and use selenium if it is in the right chemical form. The scientist says his team would like to develop a vegetable crop high in selenium. He wants to create an anti-cancer product in the foods we already eat. According to Pro. Salt, plants that take up large amounts of metal in their tissues can be used to ______. A．clean polluted soil and cure disease like cancer B．clean up harmful waste materials in soil and improve people's diet C．produce large number of micronutrients such as iron and zinc D．create food with important minerals or vitamins