| 基金项目： | This research is supported in part by grants from the National science foundation： Learning progression on carbon-transforming processes in Socio-Ecological Systems （NSF-0815993）, and Targeted Partnership： Culturally relevant ecology, learning progressions and environmental literacy （NSF-0832173）, and CCE： A learning progression-based system for promoting understanding of carbon-transforming processes （DRL 1020187）. Additional support comes from the Great Lakes Bioenergy Research Center. Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Rc~ie~nee~ Faundntinn nr fho 1 lnltod Rfato~ l~.norfrn,~nt ~~ 17 |
