他们和往常一样在晚上9点50分准时出现。They appeared on the dot of 9.50 pm as always.这则广告只能在晚上9点成人节目开始后才能播出。The advert should only be shown after the 9pm watershed.真的，我只在晚上抽烟。Seriously, I only smoke in the evenings....
Leaching of copper from chalcocite with acidic acetonitrilecopper sulphate system was studied.研究了用酸性乙腈硫酸铜体系从辉铜矿中提取铜.The paper discusses a new method for producing cupric feed copper sulfate by chalcocite and ehalcopyite....