The mechanisms and some affect factors for chemical disposal defluorination of wet - process phosphoric acid were introduced.介绍了湿法磷酸化学法脱氟的脱氟机理和影响脱氟率的多种因素....
He had retained a keen interest in the progress of the work.他对那项工作的进展一直很关心。She retained a number of copies for further annotation.她保留了许多副本以便作进一步的注解。Gary Kasparov has retained his title as world chess champion.加雷·卡斯帕罗夫卫冕了...
The cocoa industry dwindled because it became increasingly difficult to cover costs.由于越来越难以收回成本，可可产业日渐衰落。The factory's workforce has dwindled from over 4,000 to a few hundred...工厂雇员总数已经从 4,000 多人减少到几百人。Longfellow, L...