We tried to grow some copper sulphate crystals with our children.我们想跟孩子们一起制作硫酸铜晶体。Adding sulphate to the solution will give a precipitate.将硫酸盐加入该溶液会产生沉淀.More ammonium sulphate solution is being recovered in the process o...
He argues strongly for retention of NATO as a guarantee of peace.他强烈要求保留北大西洋公约组织以维护和平。The company needs to improve its training and retention of staff.公司需要改进对员工的培训和留用工作。They advocate the retention of our nuclear power pl...