“铁影壁”是元代的文物。译：The Iron Screen is（)of the Yuan Dynasty.

A . The Flinders bar B . The heeling magnet C . Quadrantal soft iron spheres D . Bar magnets in the binnacle

A . corrosive deterioration of a bearing B . inadequate air filtration C . excessive ring and liner wear D . excessive cooling of lubricating oil

A . this does not eliminate the risk of cargo shifting B . this will increase the metacentric height of the ship C . this will decrease the gravity height of the ship D . this will reduce the rolling period of the shi

A . magnetic shield B . electromagnet C . piezoelectric device D . electromagnetic domai

A . cylinder cover B . cross-head shoes C . guide-ways D . scavenging boxe

A . forged B . formed C . framed D . formatted

A . the lines of force cross the equator on a 0°-180°alignment B . the quadrantal error is 0° C . there is no vertical component of the Earth's magnetic field D . the intercardinal headings have less than 1&deg

A . east iron firings B . mild steel fittings C . small fittings D . large fitting

A . Wrought iron can resist liquids flow B . It is difficult to attain the wrought iron C . Wrought iron should be combined with cuprous alloys D . The cuprous alloys have mere disadvantages than wrought iro

A . east iron is a cheap material B . cast iron can pollute sea water C . cast iron has mere corrosive than bronzes to sea water D . cast iron is more corrosive to sea water when it meets with bronze

A . cylinder liner B . cylinder cover C . the gear box D . the scavenging box

A．sophisticated B．complex C．complicated D．intricate

是 否

The world's knowledge is said to be doubling every eight years. This knowledge【64】is stimulating economic progress. The need to collect, analyze, and communicate great【65】of information is producing new products and services, creating jobs, and【66】career opportunities. The information age is【67】considered to be a phenomenon of the service sector of the economy,【68】than a product of heavy industry. Certainly, rocketing information technologies are creating new capabilities【69】knowledge-based service spheres.【70】changes just as dramatic are【71】industry, giving people the【72】to do challenging work in exciting new ways. Manufacturing is full【73】in the information age. From design to production, the manufacturing【74】has long been information-intensive. It always has required exacting communication to describe what goes into products and how to make them. Now, computer technology is giving factory managers new【75】to gather all of this information and use it to control production. Telecommunications are producing error-free communication between the design office and the factory. Computer-aided design is enabling engineers to【76】product performances and manufacturing process on video displays, before resources are committed to build and test prototypes. Techniques like these are bringing【77】new advances in manufacturing productivity. Just as coal fueled the【78】to an industrial society, so microelectronics is powering the【79】of the information age. Microelectronic information management tools are【80】U.S. industrial capabilities, which remains【81】to America's economic wellbeing and national security. (63) A．seeking B．stimulating C．shaping D．securing

The major component of the "pitch-black dust"(Line 5, Paragraph 3) should be ______ A．iron. B．magnesium. C．silicate. D．carbon.

A．A.True B．B.False C．C.Not Mentioned

A．rates B．thicknesses C．proportions D．densities

A．Trust nature B．Trust others C．Trust thyself D．Trust God