47、Workers want more money__________ .

　　A.because their jobs are too boring

　　B.in order to enjoy more spare time

　　C.to make‘their jobs more interesting

　　D.to demand shorter working hours

　　48、The last sentence in this passage means that if we succeed in making workers’jobs more interesting__________ .

　　A.they will want more money

　　B.they will demand shorter working hourS

　　C.more money and shorter working hours are important factors

　　D.more money and shorter working hours will not be so important to them

　　49、In this passage，the author tells us__________ .

　　A.how to make workers more productive

　　B.possible factors leading to greater efficiency

　　C.to what extent more money leads to greater productivity

　　D.how to make workers’jobs more interesting

　　50、The author of the passage is probably__________ .

　　A.a teacher

　　B.a worker

　　C.a manager

　　D.a psychologist