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With Airbus’s giant A380 airliner about to take to the skies, you might think planes could not get much bigger and you would be right. For a given design, it turns (1) , there comes a point where the wings become too heavy to generate (2) lift to carry their own weight. (3) a new way of designing and making materials could (4) that problem. Two engineers (5) University College London have devised an innovative way to customise and control the (6) of a material throughout its three dimension al structure.In the (7) of a wing, this would make possible a material that is dense, strong and load-bearing at one end, close to the fuselage, (8) the extremities could be made less dense, lighter and more (9) . It is like making bespoke materials, (10) you can customise the physical properties of every cubic millimetre of a structure.The new technique combines existing technologies in a(n) (11) way. It starts by using finite-element-analysis software, of the type commonly used by engineers, (12) a virtual prototype of the object. The software models the stresses and strains that the object will need to (13) throughout its structure. Using this information it is then (14) to calculate the precise forces acting on millions of smaller subsections of the structure. (15) of these subsections is (16) treated as a separate object with its own set of forces acting on it--and each subsection (17) for a different microstructure to absorb those local forces.Designing so many microstructures manually (18) be a huge task, so the researchers apply an optimisation program, called a genetic algorithm, (19) . This uses a process of randomisation and trial-and-error to search the vast number of possible microstructures to find the most (20) design for each subsection. 10（）
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With Airbus’s giant A380 airliner about to take to the skies, you might think planes could not get much bigger and you would be right. For a given design, it turns (1) , there comes a point where the wings become too heavy to generate (2) lift to carry their own weight. (3) a new way of designing and making materials could (4) that problem. Two engineers (5) University College London have devised an innovative way to customise and control the (6) of a material throughout its three dimension al structure.In the (7) of a wing, this would make possible a material that is dense, strong and load-bearing at one end, close to the fuselage, (8) the extremities could be made less dense, lighter and more (9) . It is like making bespoke materials, (10) you can customise the physical properties of every cubic millimetre of a structure.The new technique combines existing technologies in a(n) (11) way. It starts by using finite-element-analysis software, of the type commonly used by engineers, (12) a virtual prototype of the object. The software models the stresses and strains that the object will need to (13) throughout its structure. Using this information it is then (14) to calculate the precise forces acting on millions of smaller subsections of the structure. (15) of these subsections is (16) treated as a separate object with its own set of forces acting on it--and each subsection (17) for a different microstructure to absorb those local forces.Designing so many microstructures manually (18) be a huge task, so the researchers apply an optimisation program, called a genetic algorithm, (19) . This uses a process of randomisation and trial-and-error to search the vast number of possible microstructures to find the most (20) design for each subsection. 7（）
回避条件作用是指当厌恶刺激或不愉快情景出现，个体做出某种反应，从而逃避了厌恶刺激或不愉快情景，则该反应在以后的类似情景中发生的概率增加。 下列不属于回避条件作用的是( )。
Text 1The idea of humanoid robots is not new, of course. They have been part of the imaginative landscape ever since Karl Capek, a Czech Writer, first dreamed them up for his 1921 play "Rossum’s Universal Robots". (The word "robot" comes from the Czech word for drudgery, robota.) Since then, Hollywood has produced countless variations on the theme, from the sultry False Maria in Fritz Lang’s silent masterpiece "Metropolis" to the wittering C3PO in "Star Wars" and the ruthless assassin of "Terminator". Humanoid robots have walked into our collective subconscious, colouring our views of the future.But now Japan’s industrial giants are spending billions of yen to make such robots a reality. Their new humanoids represent impressive feats of engineering: when Honda introduced Asimo, a four-foot robot that had been in development for some 15 years, it walked so fluidly that its white, articulated exterior seemed to conceal a human. Honda continues to make the machine faster, friendlier and more agile. Last October, when AMmo was inducted into the Robot Hall of Fame in Pittsburgh, it walked on to the stage and accepted its own plaque.At two and a half feet tall, Sony’s QRIO is smaller and more to,like than Asimo. It walks, understands a small number of voice commands, and can navigate on its own. If it falls over, it gets up and resumes where it left off. It can even connect wirelessly to the internet and broadcast what its camera eyes can see. In 2003, Sony demonstrated an upgraded QRIO that could run. Honda responded last December with a version of Asimo that runs at twice the speed.In 2004, Toyota joined the fray with its own family of robots, called Partner, one of which is a four-foot humanoid that plays the trumpet. Its fingers work the instrument’s valves, and it has mechanical lungs and artificial lips. Toyota hopes to offer a commercial version of the robot by 2010. This month, 50 Partner robots will act as guides at Expo 2005 in Aichi, Japan.Despite their sudden proliferation, however, humanoids are still a mechanical minority. Most of the world’s robots are faceless, footless and mute. They are bolted to the floors of factories, stamping out car parts or welding pieces of metal, machines making more machines. According to the United Nations, business orders for industrial robots jumped 18% in the first half of 2004. They may soon be outnumbered by domestic robots, such as self-navigating vacuum cleaners, lawn mowers and window washers, which are selling fast. But neither industrial nor domestic robots are humanoid. Sony's QRIO could carry out all the following work EXCEPT（）
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