保持: (维持; 使不消失或减弱) keep; hold; retain; maintain; preserve 短语和例子保持安静 keep quiet; 保持优势 hold on to a dominant [favorable] position; 保持警惕 maintain vigilance; be on the alert; 保持清洁 keep clean; 保持优良传
土壤保持: earth conservancysoil co ervationsoil conservancysoil conservationsoil consistencysoilco ervation
