4)Microfilming was a space-saving measure; once items were put onto film, they could be removed from circulation and additional shelf space would be made available for rapidly expanding collections.缩微技术是一种空间节省方法 实物一旦被拍摄成胶片,即可退出流通;这样便能为快速扩展 的藏书获得额外的货架空间。 注释:“once”引出条件状语从句。“ removed something from”译为“去掉”“从…开除” 2021/2/20 P4 End2021/2/20 P.4 End 4) Microfilming was a space-saving measure; once items were put onto film, they could be removed from circulation and additional shelf space would be made available for rapidly expanding collections. 缩微技术是一种空间节省方法， 实物一旦被拍摄成胶片，即可退出流通；这样便能为快速扩展 的藏书获得额外的货架空间。 注释: “once”引出条件状语从句。“removed something from ”译为“去掉”“从…开除