任职

hold a post;be in office;assume office
原在香港各政府部门～的中外籍公务、警卫人员可以留用。(《中英关于香港问题的联合声明》) Chinese and foreign nationals previously working in the public and police services in the government departments of Hong Kong may remain in employment./他自～以来一直勤勤恳恳努力工作。He has worked diligently since he took office./在～期间during one’s tenure of office/在联合国秘书处～work (or hold a post)in the UN secretariat