Some of the surveys included only college students; others were done with a mixed-age population.
有些调查只包括了大学生群体；其他的则针对各个年龄段的人群。
2
For special national environment, country's kindergarten mixed-age education of is different from the city's.
我国农村幼儿园存在大量的混龄教育，但由于国情特殊，农村和城市差距很大。
3
The scientists then disassembled the bees new home and forced groups of mixed-age bees to choose between three alternative nest locations, including the former nest box.