The method was established for purification of diflubenzuron by crystal technique with mixed solvents.本文论述了利用混合溶剂——结晶法提纯除虫脲的分析技术.The separation and determination of the primary impurities of diflubenzuron by liquid chrom...
露西的冷淡与世故使得巴里十分不快。Barry had his nose put out of joint by Lucy's aloof sophistication.这听上去也许微不足道，但是，相信我，它十分重要！This may sound trivial, but I assure you it is quite important!他赢了，但是赢得十分勉强。He won, but only by the skin of...