[填空题] New research shows that cleaners are some of the happiest workers in Britain, al (46) with child caters, medical secretaries, hairdressers and petrol pump attendants. The study of 35,000 employees found that the highest levels of job satisfaction were among those (47) (provide) personal service, even if the pay is poor. There are highly paid professional and managerial staff who enjoy excellent pay and conditions, but many of these appear to hate their jobs. Civil servants lie, almost at the bo (48) of the league table, with solicitors and various engineers and scientists not far behind. Michael Rose of Bath University, who led the study, said a key element of job satisfaction was the potential to work part-time and (49) (supervise). A cleaner’s job may not appeal to all, but it has hidden perks. "You can trim your hours and you don’t have a supervisor breathing down your neck all the time", he said. Petrol pump attendants, too, had a ch (50) o