Although the dream of the home robot has not died, robots have had their greatest impact i

n factories. Unimate, the first industrial robot, went to work for General Motors in 1961. Even at a time when computing power was costly, robots made excellent workers and proved that machines controlled by computers could perform. some tasks better than humans. In addition, robots can work around the clock and never go on strike.

There are now about 800 000 industrial robots around the world, and orders for new robots in the first half of 2007 were up a record 26% from the same period in 2006, according to the United Nations Economic Commission for Europe (UNECE). Demand is increasing as prices fall: a robot sold in 2007 cost less than a fifth of an equivalent robot sold in 1990, for example. Today, in car factories in Japan, Germany and Italy, there is more than one robot for every ten production workers.

Similarly, agricultural robots harvest billions of tones of crops every year. There are six-legged timber cutters, tree-climbing fruit-pickers, robots that milk cows, and others that wash windows, trucks and aircraft. Industrial robotics is a 5.6 billon industry, growing by around 7% a year. But the UNECE report predicts that the highest growth over the next three years will be in domestic rather than industrial robots. Sales of such devices, it predicts will grow ten-fold between 2007 and 2010, overtaking the market for industrial robots.

The broader application of robotics is becoming possible thanks to the tumbling (暴跌) cost of computing power, says Takeo Kanade. This lets programmers write more sophisticated software that delivers more intelligent robotic behavior. At the same time, he notes, the cost of camera and sensor chips has tumbled, too. "The processing power is so much better than before that some of the seemingly simple things we humans do, like recognizing faces, can begin to be done", says Dr. Kanade.

While prices drop and hardware improves, research into robotic vision, control systems and communications have jumped ahead as well. America's military and its space agency, NASA, have poured billions into robotic research and related fields such as computer vision. The Spirit and Opportunity Rovers (漫游者) exploring Mars can pick their way across the surface to reach a specific destination. Their human masters do not specify the route; instead, the robots are programmed to identify and avoid obstacles themselves.

It can be inferred from the first paragraph that______.

A．the first robot of the world was designed in 1961 for General Motors

B．the expensive computing power didn't hinder a robot's efficiency

C．robots controlled by computers can do most tasks better than humans

D．human workers often went on a strike when they were not satisfied in the past