案例分析题Robots1 The most sophisticated(先进的)Japanese robots, which have vision systems and work at very high speeds, are still based on American designs. Studies of robots, particularly computer control software, are considered to be generally less advanced in Japan than in America or Europe.2 Although industrial robots were originally developed as devices for simply handling objects, today their commonest uses are for more skilled work like welding(焊接)，spray-painting and assembling components.3 In Britain robot sales appropriately peaked in 1984, but have been declining ever since. This is partly because British wage rates are too low to make robots financially attractive and partly because engineers now have more experience with robots and are more aware of the difficulties of introducing them effectively.4 It has been calculated that a robot uses on average about 100 times more energy than a human to do an equivalent job.5 It is estimated that 20% of all comic book heroes in Japan are robots. This is an enormous number because comics are so popular that they make up a third of all material published in Japan.6 The reliability of robots is measured in their M.T.B.F.or mean time between failures. This has risen form about 250 hours in the mid-1970s to about 10,000 hours today (equivalent to working 18 hours a day for two years). One way robot manufactures have increased reliability is to test every single component they buy, instead of the normal procedure of just testing a small sample.7 The biggest single benefit of introducing robots claimed by Japanese companies is that they increase quality control. One programmed, the robots can work more accurately and consistently than humans, who can get tired and bored. Robots are less popular in Britain to day partly because（）

A. too much energy
B. based on American designs
C. they are too costly
D. they are not reliable
E. quality control
F. free of charge