填空题 《复合题被拆开情况》 Pay and productivity, it is generally assumed, should be related. But the relationship seems to weaken【C1】________people get older. Mental ability declines【C2】________age. That is the same for the brainy and the dim—and not【C3】________for humans: it is measurable even【C4】________fruit flies.【C5】________ minds that keep lively will suffer less than the lazy. In general, the more education you have, the more productive your old【C6】________will be. Some【C7】________decline faster than others. According to most studies, people’s numerical and reasoning abilities are【C8】________their best in their 20s and early 30s.【C9】________ abilities—those that depend on knowledge—may improve with age. For most workers, decreased abilities will【C10】________to lower productivity; only a minority will find know-how and knowledge outweighs their failing powers. Even those employees who remain highly productive will be likely to shine only in a narrow【C11】________. Academics notice this. It is less clear that employers do. Studies of supervisors’ ratings show no clear correlation【C12】________age and perceived productivity. When other employees’ views are【C13】________into account though, the picture changes; these ratings suggest that workers in their 30s are the【C14】________productive and hardworking,【C15】________scores falling thereafter. That is【C16】________up by studies of work samples, which find lower productivity among the oldest employees. A study for America’s Department of Labor showed job performance peaking at 35, and【C17】________declining. It varied by industry; the fall was【C18】________in footwear, but faster in furniture. Intellectual occupations are harder to measure, but the picture is the same. Academics seem to publish【C19】________as they age. Painters, musicians and writers show the same tendency. Their output peaks in their 30s and 40s. The only【C20】________is female writers, who are most productive in their 50s.《问题》：【C16】