勿忘归途
picture a is not worked,and picture b is worked,now,let's look at the contrast between a and b(worked,adj.处理过的)
食客小冬
前后对比分析法在战略环境评价中应用初探
Application of before and after comparison methods to strategic environmental assessment
运用微探头超声检查食管下段静脉结构的情况，进行治疗前后对比研究。
Esophageal vascular structures were examined with miniature ultrasonic probe.
成年难治性癫痫患者生活质量手术前后对比分析
Quality of life with the affection of operation in adults with epilepsy
