[填空题] Video recorders and photocopiers, even ticket machines on the railways, often seem unnecessarily difficult to use. Last December I bought myself a Video cassette recorder (36)_________as "simple to use". In the first three weeks I failed (37)_________to program the machine to record from the TV, and after months of practice I still made mistakes. I am not alone. According to a (38)_________last year by Ferguson, the British manufacturer, more than one in four VCR owners never use the timer on their machines to record a programmer: they don’’t use it because they’’ve found it far too hard to operate. So why do manufacturers keep on designing and producing VCRs that are (39)_________ to use if the problems are so obvious First, the problems we notice are not obvious to (40)_________ minded designers with years of experience and trained to understand how (41)_________work. Secondly, designers tend to add one or two features at a time to each model, (42)_________ you or I fac